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Commission on Influenza
Dedicated with respect and grateful appreciation to Thomas Francis, Jr., founder and first commission director. He contributed so much to our understanding and control of influenza. Dr. Francis' pioneering work and wise counsel were instrumental in making possible a vaccine that played a major role in controlling influenza and preventing it from becoming a significant health hazard in the military services during World War II and thereafter.
The specter of epidemic diseases, such as influenza and pneumonia, during World War II was the major stimulus that led to formation of the Armed Forces Epidemiological Board (AFEB) in 1940, called originally "The Board for the Investigation and Control of Influenza and Other Epidemic Diseases" in the Army. Its success was practically ensured simply because there was great need for solution of these always threatening epidemiological scourges for the military services and the general public. Moreover, there were key and well-informed medical scientists in America who were poised and anxious to serve their country. Need and desire are impelling ingredients for success of any venture.
A decision of great and lasting importance was the choice of Thomas Francis, Jr., a product of Yale, New Haven, Connecticut; the Rockefeller Institute, Princeton, New Jersey; and the University of Michigan, Ann Arbor, to organize and direct a team effort directed toward control of influenza. Simultaneously with directing this effort, he participated as a "sleeves rolled up" investigator. There is an old adage that says, "if you want to solve a difficult problem, ask a busy person to do it." This epitomized Francis. Impressive, in so many ways, was his insight into the solution of pressing problems sparked always by his epidemiological sense and his clinical astuteness. These attributes enabled him to help determine the proper roads to take and which routes to abandon.
The team of Commission on Influenza members that he led was the best possible group ever to be assembled, and it is to their great credit and his strong and wise guidance that the work of the Commission helped relegate influenza to the realm of effectively controlled infections. Dr. Francis' dedicated associate and friend, Fred Davenport, succeeded him as Director and Dr. Davenport, in turn, was followed by Gordon Meiklejohn, who directed activities of the Commission until its termination in 1973. Dr. Meiklejohn continues to perform surveillance evaluations that afford valuable data regarding antigenic changes through studies performed at the Lackland Air Force Base, San Antonio, Texas. This information has been most helpful in selecting the proper types of influenza virus to be incorporated in new vaccines from year to year.
This success story on influenza is an example of coordinated effort and cooperation between academically oriented and military scientists who collectively spearheaded a major effort aimed at the solution of a common health problem. Influenza, although not fully eradicated, is now effectively controlled when the public accepts and follows the available guideline recommendations. The military has a simple built-in mechanism for controlling influenza-military personnel all take the influenza vaccine.
A very important spin-off of the accomplishments of the Commission on Influenza has been the training and development of a hard core of medical investigators and educators who have filled and now grace many important professorships in our leading educational institutions. They continue to serve the Department of Defense and Public Health Service through their wise advice in determining the character of influenza vaccines and other means of control, all of which are persistent problems requiring ceaseless evaluation.
Grateful appreciation is expressed to Dr. Meiklejohn for preparing this history, which is now a document of historic and lasting importance. Ms. Patricia Graves, his devoted Research Associate, has our sincere thanks for helping re-
trieve much valuable information from numerous files, correspondence, reports, and reprints. Colonel Robert Wells and Ms. Jean Ward aided materially in this search. Without such contributions, this history would not have been completed.
-Theodore E. Woodward, M. D.
History of the Commission on Influenza
Gordon N. Meiklejohn, M.D.
When Dr. Theodore Woodward first contacted me about writing a history of the Commission on Influenza, I was somewhat overwhelmed by the prospect. As I thought about it more, it seemed to me very important to have a record of the accomplishments of this remarkable group. I had been involved in the 1943 field trials in which the influenza A vaccine was first shown to be effective in a massive field trial and have continued to work on the control of influenza in the Armed Forces up to the present time. The only other two survivors of the early days of the Commission, Drs. Jonas Salk and Edwin Lennette, have since left the influenza field.
It seemed to me that the best source of information would be the massive annual reports of the Commission. I contacted Colonel Robert A. Wells, Executive Secretary of the AFEB. He made a major effort to find them and came up with a number of the reports, but many were missing and could not be found anywhere. He was most helpful, and the reports that were found were invaluable. He provided me with a history of the first 5 years of the Commission, which Dr. Francis had written in 1945, that covered the early years very well. There still were many gaps in the story, particularly during the 1950s and 1960s. Consequently, I turned to Dr. Hassan Maassab in Ann Arbor, Michigan, for assistance. He did not have the full Commission reports but was able to provide me with the Director's summaries of all years from 1950 to 1970. From this source material I was able to find most of the main points of activity. The reader, however, must be aware of the fact that the Director's Commission reports may have been somewhat biased presentations. I may have added a bias of my own in trying to pick out what was important for the mission of control of influenza in the Armed Services. To any individuals who feel their contributions were not rightly recognized, I apologize.
At the time when the Commission began its studies there was a great deal of uncertainty and fear about what influenza might do as mobilization increased. Memory of the disaster of 1918 and 1919 was bright in the minds of many of the senior Preventive Medicine Officers and in the minds of Drs. Francis, Francis Blake, and Stanhope Bayne-Jones, who had a large part in the early organization of the Commissions. This concern is reflected in the name that they gave to the original Board, namely the "Board of the Control of Influenza and other Epidemic Diseases in the Army."
When the Commission activities began in 1941, relatively little was known about influenza. Influenza B had been discovered only a couple years earlier by Dr. Francis. The agglutination of chicken red blood cells had just been described by Dr. George Hirst in New York and Drs. Ronald Hare and L. McClelland in Toronto. Before that time, the laboratory diagnosis of influenza was based on the isolation of virus in ferrets or by complement fixation tests. The latter were not widely used. Elsewhere, during the epidemic, efforts were made to use clinical criteria to make a diagnosis, and it was obvious that these efforts were not satisfactory. Neutralization tests were carried out only in mice. These were expensive and required an enormous number of animals at a very considerable cost in dollars, time, and effort. The notions of epidemiology of influenza were rigid, and it was believed that influenza would reoccur every 2 years. This was a source of considerable concern because 1942 was supposed to be a year when an epidemic of influenza would occur.
The expected epidemic did not materialize, and to save time, Drs. Francis and Salk with their colleagues at the University of Michigan conducted a series of rather remarkable and daring experiments. They sprayed large amounts of wild influenza virus into the nasal passages of large numbers of
"volunteers" from mental institutions in Michigan. The recipients developed influenza within a very short period of time with typical symptoms and many developed ≥4 fold increases in antibody titers. Performed today, experiments of this type would be considered highly unethical. Fortunately, no one was seriously harmed by the virus challenge. In another experiment, conscientious objectors were challenged with large amounts of wild virus to determine whether an aerosol of immune serum could protect against the virus as the Russians had claimed. None of the study participants became seriously ill. Much was learned about the immunity to influenza, and it was clear that immunity was far from solid. This led the Commission to minimize its efforts to develop an attenuated live vaccine because it appeared that even infection by wild virus would not provide solid protection for much longer than 4 months. The Surgeon General of the Army at that time was especially concerned that an attenuated live virus vaccine might revert to a virulent virus of the type that caused such havoc in 1918 and 1919.
In military personnel it was accepted practice to divide troops on a random basis into vaccinated and control groups and to administer placebo injections to the controls. Field trials have never been better controlled. Once the vaccine had been declared to be effective, it was considered unethical to withhold vaccine from any member of the Armed Services. This policy was accepted by the Army in 1970.
Apart from the scientific contributions made by the members, associate members, and persons holding contracts supported by the Commission, something must be said about the personal qualifications and personal relationships of the members of the Commission. Dr. Francis served as Director of the Commission from its inception until 1957. He was admired and liked by all members of the Commission and his military colleagues. Dr. Davenport served as Director from 1957 to 1970. He also had extreme dedication and moved the Commission activities along very well. The morale of the group was exceptionally high, and the early members took on any assignments thought necessary by the Commission as a whole. They were a remarkable group of professionals who worked together in their common effort to solve a major health problem. It is hard at the present time to realize that the Commission members received no financial compensation apart from the small honorarium for each day of the meetings that they attended each year. This fact alone attests to their interest in and dedication to the public welfare.
Preparation of this history has been a time-consuming effort, but well worth it. As references were found, I could not resist reading many of them from beginning to end. All persons interested in immunity to influenza should be familiar with these early studies.
Finally, a word of appreciation must be expressed to a number of persons who were most helpful in this enterprise. Assistance provided by Colonel Wells, Executive Secretary of the AFEB, and Dr. Maassab, Professor of Epidemiology at the University of Michigan School of Public Health, Ann Arbor, has already been mentioned, and their help is again acknowledged. I am certain that all members of the Commission recognize the assistance provided by a series of Executive Secretaries of the AFEB, and particularly by Ms. Betty L. Gilbert, the Board's long-term secretary. Dr. Woodward has been most helpful and supportive in encouraging me to prepare this manuscript and in reviewing an earlier draft. Ms. Pat Graves has been exceptionally helpful, particularly in finding many of the earlier references and in the assistance in the whole project.
You will note that in some instances we were unable to find references in published articles and were forced to refer to the Director's Summary of the Annual Commission reports. Anyone who wishes to pursue further details can contact me. Every attempt will be made to provide additional data.
The Board for the Investigation of Influenza and Other Epidemic Diseases was created on 11 January 1941. During 1940 the United States had experienced a large increase in the number of recruits
introduced into the armed services in response to the war in Europe. A number of thoughtful medical authorities in the armed services, who recalled the disastrous epidemics, particularly influenza, during and after World War I, felt a need for additional assistance in developing new methods for coping with the potential risks and problems. The solution recommended was organization of Commissions made up of civilian scientists who were active in research and were well-informed of the needs in specific areas. It was conceived that Commission members would work side by side with their military counterparts in attacking these problems. Twelve Commissions were initially envisioned. Invitations were extended to highly qualified health professionals to direct these commissions and to arrange control programs required to meet projected needs.
On 10 February 1941 Dr. Blake, President of the Board, invited Dr. Francis, professor of epidemiology at the University of Michigan, Ann Arbor, to organize and serve as director of the Commission on Influenza. The invitation was immediately and enthusiastically accepted.
The original Board was called the Board for Investigation and Control of Influenza and Other Epidemic Diseases in the Army. In 1949 the name was changed to the Armed Forces Epidemiological Board.
Approximately 30 highly qualified scientists with backgrounds as epidemiologists, virologists, and educators whose interests covered wide ranges of disease categories were recruited from various areas in the United States. Each was appointed as a Consultant to the Secretary of the Army. The common goal was to detect outbreaks of influenza and institute control measures. The original Commission members and their host institutions were
Hattie E. Alexander, M.D.
M. Dorothy Beck
John W. Brown, M.D.
G. John Buddingh, M.D.
Frank A. Calderone, M.D.
Paul R. Cannon, M.D.
John H. Dingle, M.D.
Monroe D. Eaton, M.D.
Alto E. Feller, M.D.
Francis B. Gordon, M.D.
Irving Graef, M.D.
William H. Hale, M.D.
George K. Hirst, M.D.
Frank L. Horsfall, M.D.
Louis A. Julianelle, Ph.D.
Dr. Yale Kneeland
Clayton G. Loosli, M.D.
Thomas P. Magill, M.D.
Robert A. Moore, M.D.
When he rebuilt the Yale University School of Medicine, Dean Milton Witernitz was fortunate to attract Dr. Francis Blake, a Harvard Medical School graduate, to New Haven. Schooled in internal medicine, Dr. Blake ultimately chaired the Department of Medicine at Yale for 3 de cades and he simultaneously served the School of Medicine as its Dean. Francis Blake was the complete physician, an academician in the fullest sense; he was a teacher who taught by precept, a clinician accomplished in diagnosis, and a leader in curative and preventive medicine. Additionally, he was an accomplished clinical investigator and researcher in infectious diseases, particularly influenza, pneumonia, viral diseases, and the scrub typhus fevers.
It is no surprise that the original AFEB succeeded; it was blessed with the membership of accomplished clinicians and medical scientists such as J. Steven Simmons, Stanhope Bayne-Jones, and Colin MacLeod, and the presidential leadership of Francis Blake.
Thomas Francis graduated from Yale University School of Medicine where he was a protégé of Dr. Francis Blake, who introduced him to the field of infectious diseases, particularly influenza and pneumonia. This relationship led to Dr. Francis's being "passed on" to serve under Rufus I. Cole, chief of the hospital of the Rockefeller Institute in New York. At the Rockefeller Institute, Francis worked with Thomas M. Rivers, William T. Tillett, Oswald T. Avery, Homer T. Smith, Colin MacLeod, Joe Smadel, and Frank Horsfall. His interests were directed to the field of virology and, specifically, to influenza. He is credited with having been the first scientist to isolate the influenza virus in this country, in 1935. His contributions to the field of influenza research included his clarification of the antigenic shifts that characterize this complicated virus. He directed the Department of Epidemiology in the School of Public Health at the University of Michigan, where he gained national prominence when he designed the trials for, and analyzed the results of, the Salk poliomyelitis vaccine. Jonas Salk was one of his proteges.
In 1941, Thomas Francis was chosen to be the first Director of the Commission on Influenza of the AFEB. The contributions of this Commission to the prevention and control of influenza with biological vaccines is a remarkable achievement in American medicine. He was proud that his associate, Dr. Fred Davenport, succeeded him as Director of the Commission on Influenza. From 1958 to 1960, Dr. Francis was President of the AFEB.
The original members of the Board for the Investigation and Control of Influenza and Other Epidemic Diseases 12-13 May 1942
Front row, left to right: Dr. Oswald F. Avery; Colonel J. Steven Simmons; Dr. Francis G. Blake, President of the Board; Lieutenant Colonel Stanhope Bayne-Jones, Administrator; and Dr. Ernest W. Goodpasture.
Second row, left to right: Dr. Kenneth F. Maxcy; Dr. A. R. Dochez; Dr. Andrew J. Warren; and Dr. O. H. Perry Pepper.
Norman Plummer, M.D.
Elsmere R. Rickard, M.D.
James F. Rinehart, M.D.
Oswald H. Robertson, M.D.
Jonas E. Salk, M.D.
Wilson G. Smillie, M.D.
Douglas H. Sprunt, M.D.
Dr. W. M. Stanley, Ph.D.
Ernest L. Stebbins, M.D.
Members of this group met on a number of occasions and developed a program to be presented to the Board. The composition of this group was reduced to a more efficient size in 1943 when the Commission on Influenza consisted of the following members:
Monroe D. Eaton, M.D.
William M. Hale, M.D.
George K. Hirst, M.D.
Thomas Francis Jr., M.D.
Jonas E. Salk, M.D.
Elsmere R. Rickard, M.D.
The Commission was heavily weighted with former associates of Dr. Francis at the Rockefeller Institute where much of the early work on the influenza virus had been conducted. Throughout this period, the Rockefeller Foundation continued to provide personnel support to a number of Commissions.
An outline of the plan presented to the Board on 27 and 28 February 1941 was as follows.
Outline for Plan of Commission on Influenza-
I. Study of Control Measures
The proposed program for the Commission on influenza was developed and discussed with the Board along with a proposed budget estimate in the middle of April 1941. The organizational plan provided for geographic coverage of all parts of the country. The Commission planned to function during a specific outbreak by utilizing the laboratories of the State of New York and the Rockefeller Institute to cover epidemics in the first, second, third, and fourth Army areas. The Midwestern group, centered at the University of Chicago, would serve the fifth, sixth, seventh, and eighth Army areas. The ninth corps in the western states would be covered by the laboratory in the California Department of Health at Berkeley, California.
Among the goals recommended were (a) to study the protective efficacy of vaccines; (b) to investigate air sterilization by aerosols; (c) to study the effectiveness of masks to control infection; and (d) to collect data on the clinical, pathological, and bacteriological aspects of the investigation. In addition, during field studies, epidemiological data would be collected on the character and dissemination of the illnesses, the type of influenza virus involved, pathological studies on fatal cases, and evaluation of various forms of treatment.
A series of recommendations was made to provide for one mobile laboratory in each of the geographic divisions and to integrate studies with those of other Commissions, such as the Commissions on Pneumonia, Streptococcal Diseases, and Epidemiological Survey. It was also proposed that a trial mobilization be organized as soon as possible to test the mechanisms by which the Commission might function in the event of an epidemic. It was considered essential that the investigative units work at the site of the outbreak in collaboration with the appropriate medical armed forces personnel.
The original proposal called for a total budget of $53,200 for each of the three units, for a total of $159,600 to be utilized as follows:
It is significant to mention that salaries of most of the investigators were derived from their own institution or were through funds provided by the Rockefeller Foundation; it was assumed that individual investigators would receive supplemental compensation only during their assigned duties in the field.
The original proposal was consequently revised and reduced. The Rockefeller Foundation provided, without cost, the facilities of their laboratories in New York and California and offered the Medical Department of the Army the use of their laboratory services and the opportunity to obtain and store materials for the Commissions purposes. Arrangements were made for the close scrutiny of weekly surveillance reports for possible outbreaks of influenza by the members of the Commission of Acute Respiratory Diseases. Authorization was given for (a) experimental trial of an influenza vaccine should the vaccine of promise be available and a suitable opportunity arise; (b) studies of the efficacy of respiratory masks; (c) laboratory studies of materials and samples collected in the field bearing on the etiology, epidemiology, and immunology of influenza and its complications.
The contract between the University of Michigan School of Public Health and the Commission on Influenza was completed on 15 December 1941. From this time on, the Ann Arbor unit became the focal center for the Commission and remained the core unit throughout the Commission's existence. The Commission had by this time in December 1941, reached a point of coordinated intent, alert to the
techniques of early detection of influenza disease at any site. It was prepared primarily to study the medical features of influenza. There was little else available except application of general public health measures to control virus infection.
DEVELOPMENT OF INFLUENZA VACCINE
The possibility for development of an inactivated vaccine, effective for prophylaxis against influenza, had been the main focus of attention since 1935 when Drs. Francis and Thomas McGill had first shown that active virus cultivated in tissue culture produced antibody in humans without producing an illness.1 It was also well established that vaccination could be effective against influenza virus in mice. There was wide experience in using live virus given intranasally in humans without producing overt illness.
To obtain further information on the usefulness of immunity produced by live wild influenza strains administered intranasally, Dr. Francis and his colleagues at the University of Michigan conducted a remarkable series of studies in "volunteers" at Ypsilanti State Hospital. The results were surprising when 27 of 30 men developed sharp attacks of influenza within 24 hours or less. The discovery of infection among nonlitigated individuals in the same quarters was obtained by serologic tests.
Four months later the 27 persons described above were challenged with a different preparation of the same influenza B virus. The virus induced fever and clinical illness in many of the same group, accompanied in eight persons by additional antibody rises. There was evidence that the earlier infection had exerted some effect, because a milder illness occurred in most of those previously infected. A spray of irradiated influenza virus material produced no significant reaction, which indicated that the favorable effects observed were related to active virus.2
The fact that these persons lacked very strong resistance to the same virus, after a period of 4 months, raised serious doubts about the probable efficacy of vaccination with live attenuated strains. Furthermore, the consideration that inoculation of humans with live attenuated virus carried the possibility of a revival of virulence that might initiate another epidemic. The Surgeon General, Major General Norman Kirk, concluded that this was an inadvisable risk; hence, further work with live vaccine was not carried out at this time.
It was concluded that (a) vaccine must be given before the appearance of influenza because of the rapid spread of the virus, (b) large numbers of individuals were needed to obtain definite results, (c) these studies would have to be performed in vaccinated and unvaccinated (control) population groups under similar observation, and (d) the vaccine evaluations must be regarded as experimental. Always there was concern that an epidemic of influenza A might appear before the study got underway. Considerable attention was given to evaluation of methods of demonstrating vaccine effectiveness and detection of antigenic drift.
It was ultimately decided that the best source of virus for the vaccine would be infected egg allantoic fluid inactivated with Formalin and kept at 4° C in the fluid state. Lyophilization reduced the amount of available antigen. Antigenicity of the vaccine was planned to be tested in mice inoculated intraperitoneally. All vaccine testing was conducted on an experimental basis.
1941 and 1942
The Commission was authorized by the Board to undertake a study of influenza vaccine of type A and B viruses conducted by Dr. Monroe Eaton in California should an appropriate opportunity arise. Two thousand doses of vaccine were provided by Dr. Hirst of the International Health Division of the Rockefeller Foundation. The process of finding a satisfactory study group was abandoned with the entry of the United States into World War II. It was considered impractical to undertake a study in
troops, particularly when influenza was not prevalent at the time.
After consultation with five commercial firms (including Parke Davis and Co., Lilly, Lederle, Sharp & Dohme, and Squibb) plans were made to prepare 100,000 doses of inactivated vaccine from allantoic fluid. It was concluded that this could be accomplished in 4 to 8 weeks at a cost of 7 to 60 cents for a 1.0 mL dose. Each company then was asked to furnish sample lots of 250 mL. Samples were tested in mice for vaccine potency in Dr. Francis' laboratory in Michigan. There was extremely wide variation in antigenic potency, and sterility was also a problem.
1942 and 1943
Because influenza A epidemics were said to occur every 2 years, there was concern that an epidemic caused by the virus would occur in the years 1942 and 1943. Efforts to organize an evaluation within the armed services were unsuccessful. Two civilian-sponsored trials were conducted, the first under the direction of Drs. Wilson Smillie, Magill, and Norman Plummer at Cornell University through the University Health Service. A total of 2,885 student volunteers were enrolled in the study, of whom 1,673 received vaccine and 1,213 served as controls. Serum specimens were collected from one-sixth of those enrolled in the study before, 3 weeks after, and 4 or 5 months after vaccination. The vaccines, manufacturers, and method of preparation are shown below:
A number of epidemiologists had tried previously to predict when influenza epidemics were likely to occur. The prevailing dogma was that influenza A occurred every 2 or 3 years and influenza B every
Vaccines Used in Cornell University Study
5 or 6 years. Dr. Alex Langmuir, Senior Epidemiologist at the Centers for Disease Control, tended to support this belief. This worked to the advantage of Dr. Davenport and me. Each year at the Atlantic City meetings of the American Society of Clinical Investigation and The Association of American Physicians, we would wager with Alex about what type of influenza A or B would occur during the next winter. Dr. Langmuir, with his profound knowledge of epidemiology, never had any doubts of what was coming. My friend, Fred Davenport, and I had observed enough outbreaks of influenza to realize that no prediction was justifiable and that whatever influenza had occurred in the past was no longer applicable. More rapid means of transportation provided by air travel had changed all the earlier rules. It seemed folly to predict what might happen.
Sera were also collected from all persons who reported to the Health Service with acute respiratory disease. No epidemic of influenza occurred, and it became obvious that influenza vaccine had no influence on other types of respiratory diseases. The serologic results suggested that influenza B had occurred but there was no evidence that it had affected the number of visits to the clinic. The reactions to the inoculations were of interest. Eleven percent of those who received vaccine experienced systemic reactions compared with 2.1% in the controls. Local reactions also were observed in 8.7% to 17.5% of individuals who received vaccine compared with 0.5% in the controls.
When no influenza appeared, Drs. Francis, Salk, and Harold Pearson at the University of Michigan conducted experimental trials in the inmate population at the Ypsilanti State Hospital in Ypsilanti, Michigan, and Eloise Hospital and Infirmary, Eloise, Michigan. Both institutions were occupied mainly
by mental patients. The vaccine was prepared by absorbing the virus onto chick embryo red blood cells and then eluding the virus from the red cells. The virus was inactivated with Formalin and a mercurial bacteriostatic agent was added. Blood specimens were obtained from approximately 10% of the vaccinated and control groups before and 2 weeks after vaccination. The mean hemagglutination inhibiting (Hemagglutination Inhibition) titers of the vaccinated group against types A and B were increased approximately nine- and eightfold, respectively. The geometric mean titers decreased by approximately 35% after 4 months, and at the end of a year the titers decreased by approximately 50%. Influenza A infection did not appear in this population. Influenza B apparently infected approximately 20% of this group even though clinical influenza was not detected in those persons who reported with respiratory illness. Thus, it appeared that influenza B occurred essentially as a subclinical infection.3,4
Despite the lack of an epidemic and in an effort to gain information regarding the effectiveness of the vaccine, groups of vaccinated and untreated subjects were tested for resistance by actual intranasal spray with active virus. Two milliliters of the virus were delivered into each nostril of each volunteer with an atomizer. One hundred two (102) men were exposed to artificial infection with a strain of influenza A virus (A/Baum/40), which differed from the PR/8 strain used in the vaccine. The control group of the subjects had not been previously vaccinated. Fifty percent of the controls developed temperature elevations of 100°F or more associated with clinical manifestations. Of those vaccinated 4.5 months earlier, 32% had similar reactions, whereas of those who were vaccinated 2 weeks previously, approximately 14% had fever as high as 100°F, but none as high as 101°F (see Appendix 1).
Ninety-six (96) men were exposed to influenza virus, type B, in the same manner. Of the 27 unvaccinated controls, 41% developed fever of 100°F or more with clinical symptoms. Of the 69 who had been vaccinated up to 4.5 months earlier, 7% to 13% had fever of 100°F; in no instance did it reach 101°F (see Appendix 1).
These results showed clearly that the vaccine exerted a protective effect against artificial infection of a severe degree. There was a tendency for resistance to be related to higher levels of antibody. However, even at the lowest antibody level, only about half the individuals became ill. The results well confirmed the concept that vaccination could induce resistance.
1943 and 1944
In June 1943 authorization was obtained from The Surgeon General of the Army to conduct a vaccine study against influenza in the Army Student Training Program (ASTP) unit at Cornell University and other Army personnel at a few selected posts. A meeting was held on 2 September 1943 in the Office of The Surgeon General to discuss this program. The following individuals were present:
Dr. Francis Blake
It was agreed that vaccination in the various ASTP units be put on a compulsory basis with half of each unit to receive vaccine and half the control inoculum. The test vaccine would be of the eluate type with vaccination contemplated to begin in October.5 If no influenza appeared before 15 January 1944, the vaccination was to be repeated. A follow-up plan provided that approximately 5% of the vaccinated subjects and 10% to 25% of the controls would provide blood specimens for antibody studies at the time of vaccination and 2 weeks later. The purpose of taking blood specimens from a larger number of controls was to obtain information on the frequency of subclinical infections. Throat washings and paired sera were to be obtained from as many of the volunteers with cases of respiratory infection as possible. Two virus strains, namely PR/8 and the Weiss strain, an influenza A virus isolated in an Army camp in May 1943, would represent the A component. The B component would be equal to the A component and would be made up entirely from the B Lee strain of virus. The contemplated arrangements concerning the university groups and their supervision by the members of the Commission on Influenza were
Dr. Monroe Eaton
Dr. George Hirst
Dr. Thomas P Magill
Dr. William M. Hale
Dr. Thomas Francis, Jr.
Dr. Jonas E. Salk
Dr. Wilson G. Smillie
Dr. Elsmere R. Rickard
Obligingly, an epidemic of influenza appeared in sufficient extent and severity and covered the United States with readily detectable illness. It was a mild, and, in most instances, an uncomplicated disease. The scope of the epidemic was observed to be higher than in any other epidemic since 1918 and 1919.
On the basis of clinical results, it was found that among 6,263 vaccinated individuals, there was an attack rate of 2.22%. Among the 6,211 control participants, the attack rate was 7.11%. Estimated vaccine efficacy (VE) was 69%.6 This trend was the same in all study groups. In some areas the ratio of control to vaccinated was as high as 6:1. In California, however, the trend was less pronounced. There was a suggestion from the serologic data obtained that the virus in California had shown some antigenic change and differed more from the Weiss strain contained in the vaccine than at the other institutions.
It was also observed that in both vaccinated and control groups, the greatest percentage of cases of illness occurred in those individuals with low antibody titers. Persons with the higher antibody titers, whether produced through natural causes or by vaccination, were much less frequently affected.7,8
It was also noted at Iowa9 and at City College of New York,10 where the influenza appeared before the vaccination was completed, that in the first week after vaccination there was no difference between the incidence of disease between controls and the vaccinated subjects. Thereafter, incidence in the groups deviated with a sharp reduction in the frequency of illness in the vaccinated population. Cases of pneumonia, which were few in number, occurred almost entirely in unvaccinated persons. In institutions where Streptococci were isolated from the pharynx of up to 20% of persons, pneumonia cases were few in number. No deaths were recorded among the approximately 12,474 individuals under observation. Subclinical infections occurred in up to 40% of individuals. Toxic reactions to vaccine were considered unimportant. Two cases were presumed to be due to a sensitization reaction to the egg component of the vaccine: an asthmatic reaction in one patient and an urticarial rash in another. Systemic reactions occurred in 2% to 3% of those vaccinated and were similar to the mild reactions observed after typhoid vaccination. When the data were sufficiently compiled to provide a clear indication of the
effect of the vaccination, a conference was held at the Rockefeller Foundation on 2 February 1944. The participants were
Dr. Francis G. Blake
Dr. Joseph W. Beard (by invitation)
Dr. Thomas Francis, Jr., Chairman
Dr. Wendell M. Stanley (by invitation)
Dr. George K. Hirst
Colonel Stanhope Bayne-Jones
Dr. Thomas P. Magill
Colonel Karl R. Lundeberg
Dr. Jonas E. Salk
Lieutenant Colonel Arthur P. Long
Major Norman Plummer
It was agreed that the results obtained had shown that the vaccine used was highly, although not completely, effective in preventing influenza A.
Dr. Francis was asked to prepare a statement of the results obtained in the Commission's studies on the effectiveness of vaccine in experimentally induced influenza, the field trial of vaccination against influenza A, reactions to the vaccine, and specifications for the production of vaccine. This statement was anticipated to serve as a basis for evaluation and recommendations to The Surgeon General. After full discussion, Commission members voted to recommend the following to The Surgeon General: (a) All troops deployed overseas and other military personnel in this country should be vaccinated against influenza, as the amount of vaccine permitted. (b) Special controlled field trials should be continued with modifications of influenza vaccine. These should be undertaken on a selected basis under the supervision of the Commission on Influenza in certain units of the Army, at an appropriate time when vaccine became available. (c) The type of influenza vaccine currently used should be the same as that used by the Commission in the ASTP test (mixed A present and B formalinized vaccine), according to the specifications in the statement submitted by Dr. Francis.
Further conferences with representatives of biological firms were held. Finally, on 1 July 1944 the program was officially approved. This provided for the acquisition of 10,000,000 doses of vaccine for use throughout the entire U.S. Army, if necessary. The vaccine to be prepared was to be the eluate from chick embryo erythrocytes with the possibility of changing to other procedures as new information warranted.
TOXICITY, STABILITY, ANTIGENICITY
In January 1944 Dr. Joseph Beard11 of Duke University and Dr. Wendell Stanley12 of Princeton University, each of whom had worked under Office of Scientific Research and Development contracts, suggested that the influenza vaccine could be prepared by Sharples centrifugation with a high degree of purity. This procedure was conceived to increase the amount of virus in the vaccine and at the same time remove practically all the nonvirus protein. At the time there was no information available on the stability of the purified vaccine or on its toxicity. Stability and toxicity were thought to be caused by the amount of virus in the vaccine rather than the egg protein.
At a conference held on 2 February 1944, it was recommended that investigation of more purified concentrations of the vaccine prepared by Sharples centrifugation be sponsored and supervised by the Commission on Influenza through collaboration with Drs. Stanley and Beard. Controlled field trials were contemplated. The field trials were proposed to discover the following: (a) The protective value of the vaccine in animals; (b) the degree and duration of antibody response in humans; (c) the frequency and severity of reactions in humans with different concentrations of virus; (d) the practicality of com-
mercial mass production, because any increase in the number of fertile eggs required per dose proportionately increased the cost; and (e) prophylactic value in humans.
The eluate vaccine that had been proven effective in the 1943 field trials served as a point of reference. It was estimated that the amount of virus in that vaccine was about 0.2 mg/mL.
Dr. Salk, who worked at Eloise Hospital in Michigan with vaccine prepared by Dr. Beard, found that three of six individuals given vaccine containing 0.2 mg of B Lee influenza virus, developed fevers of more than 100°F with troublesome symptoms; in the controls who received the PR/8 strain, none showed fevers over 100°F. Three of the six who received 0.4 mg of the B virus vaccine developed febrile reactions between 101'F and 102°F with overt manifestations. Three of the six persons given this amount of type A vaccine had fevers of 100°F. These data suggested that this dosage level represented the upper limit of tolerance.
Dr. Hirst at West Coxsackie, New York13 and Dr. Salk tested different dosages using vaccines by Dr. Stanley's methods and vaccine prepared by Sharp & Dohme (double cycle centrifugation).12 Of those men who received 2.0 mg of vaccine, 80% had fever and symptoms of toxicity that clearly indi cated that this dosage was unacceptable. A dose of 0.2 mg elicited fever of 100°F in 4% to 15% of subjects. The Commission vaccine referred to earlier had induced a slightly higher incidence of reactions. Dr. Hirst gave a few volunteers 10 mg of vaccine; all had sharp, severe reactions. It appeared that the desired amount of antigen should probably not be more than 0.2 mg.
Another batch of vaccine using Dr. Stanley's method prepared by the Squibb Company caused considerably less toxicity. Using 0.5 mg produced similar reactions in only 16% of the subjects, and a preparation of eluate vaccine made by the same firm produced the same results.
Dr. Beard and his associates in Durham, North Carolina, conducted another study on the toxicity of vaccine in swine. This was performed on his premises, which he had converted into a large pig farm. The swine received doses of virus varying from 0.125 mg to 2.0 mg. In animals that received 0.5 mg or more of vaccine, general reactions were noted followed by loss of weight. These studies helped define the upper limit of acceptability.14,15
Over the 16-fold range of dose employed, antibody response differed by only twofold. Revaccination with the same dose at 1-week intervals showed little effect. As the interval before the second dose was lengthened, the response increased and reached higher levels; antibody titers were more prolonged, regardless of the amount of virus injected. These results were of interest because of the insignificant difference in antibody response that resulted from relatively large increases in the amount of antigen used. Dr. Beard also tested alum-precipitated vaccine and concluded that there was little gained by this procedure.
Drs. Hirst and Salk followed the serologic response to different amounts of virus in the vaccine. Dr. Hirst found that the antibody response to 2.0 mg was definitely better than 0.2 mg after 2, 18, or 60 weeks. The results obtained with vaccine used by Commission members in 1943 fell between the three. The response to the Weiss strain of influenza A was less than the PR/8 strain of A or the Lee strain of influenza B. Although these data indicated the possible advantages of doses approaching 2.0 mg in humans, these were counteracted by the fact that five to six eggs were needed to obtain that amount of virus. In addition, the toxic reactions in humans were proportional to the virus concentration. This was taken to indicate that the amount of virus, as presently prepared, was probably appropriate. Stability studies at Michigan and in Dr. Stanley's laboratory showed that vaccine prepared by centrifugation was stable at 4°F for as long as 1 year.
On 30 March 1945 at The Surgeon General's Office, a meeting was held that included representatives of the National Institutes of Health (Dr. Joseph Bell), Army Procurement of The Surgeon General's Office, and Drs. Beard, Stanley, and Francis. Centrifugation was accepted as an alternate method for production of influenza virus vaccine for Army use. The technique to be employed was essentially that described in Dr. Stanley's publication.12 It was specified that the material would contain 0.03 mg/mL of nitrogen of stated minimal agglutinating titer. Despite some contrary opinions, it was concluded that the potency test in mice was desirable and should be retained. The producers now had a choice of two approved methods.
On 21 June 1945 Commission members and representatives of The Surgeon General's Office met at the Rockefeller Institute in New York City to consider the subject of vaccination. Recognized epidemics of influenza B had occurred during May and June of that year. Those in attendance were
Dr. Francis G. Blake, President of the Board
Major John H. Dingle
Dr. Thomas Francis, Jr., Director of the
Captain George K. Hirst
Dr. Ronald Hare of Toronto, Canada (by invitation)
Dr. Joseph W. Beard
Dr. Alto E. Feller
Dr. William R. Hale
Dr. Thomas P Magill
Dr. Jonas E. Salk
Dr. Wendell M. Stanley (by invitation)
Dr. Wilson G. Smillie
For The Surgeon General's Office:
Colonel Elliott S. Robinson
Major Norman Plummer
At that time there was a general discussion of the desirability of vaccination with the aim to avoid the effects of a gradual intensification of the disease such as had occurred in 1918. Colonel Robinson stated that as of 1 June 1945, 3,000,000 doses of vaccine had been delivered. According to planned schedules, enough vaccine for recruits would be on hand by 1 October 1945.
The following recommendations were made to the AFEB: (a) Provide influenza vaccine in sufficient amounts; (b) if there was no epidemic of sufficient severity to justify vaccination earlier, vaccination should be carried out by the Army during October 1945; (c) further field trials should be carried out if suitable locations could be found. Dr. Stanley stated that vaccine prepared by centrifugation would be available for these purposes.
A committee chaired by Captain Hirst was appointed to study and make recommendations concerning common laboratory procedures. Drs. Beard and Stanley were also requested to study the methods of estimating influenza virus quantitatively, which, at that time, gave quite different results in different laboratories.
The recommendation for the use of vaccine in the Army was presented by Dr. Blake to The Surgeon General in a communication dated 2 July 1945. It was approved by General Kirk on 10 August 1945. Final approval of the Secretary of War was recorded on 25 August 1945. The program of vaccination with eluate was carried out by the Army in October and November 1945.
An increasing incidence of influenza B developed in the United States during November and December 1945. It was reported that Army personnel who were vaccinated experienced a much lower incidence of illness than unvaccinated Naval and civilian groups.
The results to that point had demonstrated that vaccination effectively prevented epidemic influenza A. However, this was only one important step in the development of an effective vaccine prophylaxis for this important epidemic scourge. Yet, it was a major accomplishment and served as a stimulus to find more effective vaccines. The various progressive steps were made not only by members of the Commission, but by numerous associates and assistants. They called on, without reservation, the President of the Board, other Board members, General J. Steven Simmons, General Bayne-Jones, and Preventive Medicine officers continuously for their advice and assistance in making arrangements for the investigative work. Contributions of pharmaceutical firms to solution of production problems and safety matters were very significant. These firms continued to investigate with methods and procedures at their own expense, as requested, and contributed valuable suggestions to make procurement of vaccine for testing possible. The experience gained in the process of virus cultivation, harvesting,
and control of contamination was both troublesome and costly. The field trial in ASTP units represented a unique example of the conduct of difficult experimentation made possible through the cooperation of groups of many persons engaged in a wide variety of activities.
INTRANASAL SERUM PROPHYLAXIS
The possibility that influenza could be prevented by intranasal administration of appropriate immune serum had been shown by results reported by some investigators in studies with mice. In addition, the interest in this approach had been heightened by the report in 1939 of A. A. Smorodinsev and his associates in the USSR. He reported that administration of spray containing as little as 2.0 mL of immune horse serum in humans once in 2 weeks had reduced the incidence of influenza infection by 10-fold (82/1,000).16 (In California a prominent magazine featured, under a banner heading reading "Flu is Through," a photograph of 12 men in naval uniforms each with a tube in his mouth connected to a chamber that was said to contain atomized immune horse serum.) It was considered important to gain information on the efficacy of this procedure as an emergency measure alternative to uniform vaccination.
The Army Epidemiological Board in May 1942 recommended that the Commission on Influenza undertake studies on the prophylactic and therapeutic effect of convalescent serum given intranasally should the proper opportunity arise.
Discussions were held with Dr. Paul Cannon, who was interested in local immunization of the respiratory tract, and with Dr. O. H. Robertson whose group was working with aerosol techniques and routes of infection. Dr. Clayton Loosli, who had been working with Dr. Robertson, undertook the developmental aspect of the investigations. A subcommittee of members of the Commission comprising Drs. Cannon, Irving Gordon, Loosli, Robertson, and Francis was formed as an epidemic study group in 1942.17 However, no epidemic occurred during 1942.
Volunteers for experimental studies were recruited at a camp for religious conscientious objectors at Wellston, Michigan. Dr. Salk joined the Committee members to help in conducting studies there. After it was shown that the influenza B virus preparation that had been planned for use was unsatisfactory, allantoic fluid was used containing a new strain of influenza A isolated in 1940. The results of the two completed experiments that were performed are summarized in Appendix 2.
Two experiments were performed, each in healthy, husky volunteers. In Experiment 1, the allantoic fluid produced illness in almost all of the volunteers who received 1.0 mL of saline aerosol before an aerosol of the virus. With no exception, the control volunteers who received immune serum followed by inactivated virus escaped illness. The serum had no demonstrable effect.
Experiment 2 was carried out with a different preparation of virus. On the assumption that the virus challenge might have been too strong, the amount of high titer convalescent serum was far greater than that used in the first experiment. It was given in three doses before administration of the live virus and also 7 and 17 hours after the virus challenge; in all, a total of 37 mL were given. The second group received doses of saline at the same intervals and in similar amounts. The test was milder in that only 8 of 15 (53%) controls were ill, and the febrile reactions were less marked than in the first experiment. Of those who received immune serum, 11 of 16 (69%) had fever of 100°F or more; the distribution of severity was approximately the same as in the controls. There was no effect on the incubation period (see Appendix 2).
To gain a better idea of the amount of virus in the challenge preparation, the virus was titrated in volunteers at the Ypsilanti State Hospital. Results of the titrations are also shown in Appendix 2. It appeared that the amount of virus was by no means excessive.
The evidence was conclusive even though unexpected. Further studies were not carried out because the results of the vaccination study in 1943 were far more satisfactory. It was hoped to carry out further studies during the epidemic of 1943, but suitable conditions did not occur.
Investigation of the contraindications caused by sensitization to the various antisera that had been proposed were carried out in guinea pigs by Dr. Cannon's group. Normal horse serum, "despeciated" anti-influenza horse serum, Lilly's purified horse serum, goat serum, swine serum, and crystalline egg albumin were all tested in guinea pigs. All produced anaphylactic sensitization. This provided fair warning against continued use of such sera in humans.17
METHODS FOR DIAGNOSIS AND ISOLATION OF VIRUS
A number of investigators undertook studies to develop protocols for rapid diagnosis of influenza infection. The agglutination-inhibition test of Hirst proved to be of great value, and a number of modifications were made to expand the value of the test.18 One test that had been extensively used was the one described by Dr. Salk. 9 The time required for identification of influenza virus in the throat washings had been reduced to between 36 and 72 hours. Drs. Rickard, Eaton, and Hirst each attempted an evaluation of different procedures with somewhat different results. Nonetheless, both amniotic and allantoic inoculations served to speed the diagnosis of influenza considerably.
The possibility of finding adjuvant materials that would heighten the antibody response and prolong immunizing effects was undertaken particularly by the Ann Arbor, Michigan, groin, and their studies suggested that the adsorption of virus to calcium phosphate was not promising.20
CENTER FOR THE STUDY OF STRAINS OF VIRUS
One of the constant problems encountered was whether a virus strain was suitable for vaccine production. There was enough antigenic heterogeneity to raise serious questions about the capacity for one strain to induce immunity to others of the same type. In the 1943 epidemic the suggestion had been advanced that the vaccine had not stimulated a satisfactory antibody response to the current epidemic strains. The PR/8 strain of influenza A was consistently shown to be one of the most effective ones studied.
To gain further information about these characteristics, Dr. Magill accepted the invitation of the Commission on Influenza in 1944 to establish a center for the collection of strains of virus submitted for study of their antigenic patterns and immunizing potencies.21 His work was also to include the preparation of specific antisera and a broad hyperimmune serum for purposes of strain identification. In this connection it was noted that Dr. Francis reported apparent variation in two lines of the same strain of virus grown in different media.
INFLUENCE OF PHYSICAL FACTORS ON INFLUENZA VIRUS
In the course of studying the aerial transmission of respiratory infection, Dr. Loosli evaluated the influence of temperature and humidity on survival of influenza virus. In the experimental spray chambers22 he found that the virus remained infectious at low humidity (17% to 24%) for as long as 24 hours. As the humidity progressively increased, the period of survival was reduced so that at humidity of 80% to 90% it was infective for no longer than 1 hour. The same trend was followed with virus found on the floor in dust. What relation these facts had with the general epidemiology of influenza was a subject of speculation.
TOXICITY OF INFLUENZA VIRUS FOR MICE
In studying a strain of influenza isolated in 1943, Dr. Hale noted that intracerebral inoculation of mice caused convulsions. These were not associated with multiplication of virus in the brain. This convulsion-producing factor was heat labile and was absorbed and eluted from erythrocytes with the virus activity; it was neutralized by specific antibody23 The significance of this intrinsic toxicity of the virus in relation to the symptomatology and pathogenesis of the disease was considered important for future studies.
DIAGNOSTIC TESTS FOR PSITTACOSIS-LGVA GROUP OF VIRUSES
Dr. Francis Gordon at the University of Chicago investigated the specific diagnosis of Psittacosislymphogranuloma venereum group (LGVA) closely related group of viruses. Sera prepared in chickens were shown by neutralization tests to have a high degree of specificity. In the course of these tests, information was obtained on nonspecific reactions to chicken sera that had probably been the chief obstacle to the use of serum from chickens in serologic tests.24
During the fall and winter of 1942 the increased prevalence of atypical pneumonia in the Army and the lack of information regarding its etiology justified an extensive investigation. Drs. John H. Dingle and G. John Buddingh, who had been members of the Commission on Influenza, joined the Commission on Acute Respiratory Disease (CARD). As work expanded, Dr. Alto Feller joined the CARD group. The Commission on Influenza provided a laboratory technician and a statistical assistant. In February 1942, Dr. Francis spent 2 weeks with the CARD at Camp Claiborne in Louisiana, aiding in the investigation and participating in other aspects of the study. Following this, the Commission on Influenza laboratory at Ann Arbor, Michigan, in an effort to isolate virus, tested throat washings in mice from nine patients and sputum from two characteristic cases at Camp Claiborne, Louisiana. Eggs, mice,
Dr. Clayton Loosh was an Idahoan who attended the University of Chicago. He worked closely with Dr. O. H. Robertson. He was particularly helpful to the Commission in developing effective means of delivering virus in suspension for experimental challenges in human beings. He was also instrumental in developing the "glycolizers" that were used to create suspension of propylene glycol in the air. These were widely used at Camp Detrick for the protection of the staff who were working with particularly lethal agents. Later, after he became Dean of the School of Medicine at the University of Southern California, he continued to be an active participant in the affairs of the Commission. He worked with mice, trying to produce a controlled antigenic change in the virus. He also obtained interesting, and somewhat surprising, data on the effect of Los Angeles smog on mice infected with influenza virus. At one point, it appeared that the smog actually helped the animals, rather than hurt them. He was a very friendly person with broad interests who was exceptionally well qualified to be dean of a medical school.
cotton rats, hamsters, ferrets, monkeys, rice birds, doves, and chickens were used. No influenza virus was recovered. In four instances, a virus similar to the meningo-pneumonitis virus of mice was recovered from the sputum or throat washings by passage through mice or rice birds. In each of these instances, the patients were blacks who had significant levels of complement-fixing antibodies to LGV in their sera. Serologic tests of the patients against influenza A and B were negative. The results of complement fixation tests using both meningo-pneumonitis and psittacosis virus performed with serum collected from more than 300 patients and controls were essentially parallel. Although a relatively large number of persons showed positive reactions, it was uncommon to find any increase in titer during the course of illness. Analysis of the results showed that positive results were concentrated largely in blacks, suggesting that this was probably a reflection of a common antigen with LGV virus.
From July to November 1942, Dr. Feller, working in the laboratory in Michigan, in an effort to isolate a virus, tested large numbers of specimens from a variety of military bases in the Midwest. In two instances, viruses resembling meningo-pneumonitis were recovered. One of these patients showed a significant antibody rise in complement fixation tests.
With the establishment of the permanent CARD at Fort Bragg, North Carolina, the materials stored at Michigan were transferred to its laboratories, and investigations of atypical pneumonia at Ann Arbor, Michigan, were discontinued. Repeated clinical and epidemiological studies at Fort Custer, Michigan, led Dr. Francis to the opinion that "atypical pneumonia" was occurring in the Army probably as a single entity. The relatively low transmissibility and its random distribution suggested that pneumonia might be a rather infrequent manifestation of a more common disease in the trachea and upper respiratory tract. The whole course of the disease differed from that of influenza in that the peaks of the outbreaks were long plateaus rather than sharp spikes and only the recruits were infected. With influenza, both recruits and permanent personnel were affected. There were also sharp differences in the clinical manifestations of the two diseases.
The solution to the cause of this disease became highly competitive. Dr. Frank Horsfall and his group at the Rockefeller Institute reported transmission of an agent to mongooses.25 This group also isolated a Streptococcus (M.G.) and showed that the agglutination titers of convalescent sera of many patients with atypical pneumonia were higher than those in the acute phase sera.26
Dr. Eaton had demonstrated in 1942 that when sputa from patients with atypical pneumonia were inoculated into cotton rats or hamsters, small lung lesions developed in a large proportion of the animals.27 Serial passage of these lung specimens produced even better lesions, but it was found that a number of wild viruses was being picked up. Material from patients at Cowell Memorial Hospital in Berkeley, California, when inoculated into eggs, was shown to produce a similar pneumonic lesion and could be passed using a suspension of amniotic fluid, and trachea and lung of the embryo.28 It was shown in neutralization tests that fourfold increases in antibody titers were obtained in 68% of the aired sera from patients with atypical pneumonia. An additional 16% showed a twofold rise.29-31 These were the same patients in whom rises in titer of cold agglutinins had previously been demonstrated.32 Dr. Eaton and his collaborators were convinced that they had excluded wild animal viruses, but others refused to accept their interpretation until Dr. Robert M. Chanock at the NIH showed that the agent (Mycoplasma pneumoniae) could be grown on synthetic media.33 Drs. Eaton of the California Department of Public Health and K. F. Meyer of the Hooper Foundation of the University of California differed so strongly on the importance of psittacosis-like virus that they stopped speaking to one another.
Under the direction of Dr. Hattie Alexander, a laboratory was organized in 1941 for the typing of Haemophilus influenzae and for the preparation of diagnostic reagents. Antisera of various types were
produced in rabbits on the basis of agglutinin nitrogen. Beginning with the influenza epidemic of 1943 and continuing through the spring of 1945, a study of throat cultures was carried out on normal young adults to obtain background information on severe pneumonia. No encapsulated strains of H. influenzae were found. Only 2% of those cultures were potentially encapsulated. Tests on the susceptibility of these organisms to sulfonamides revealed considerable variation.34 Classification of H. parainfluenzae was also attempted and suggestive evidence of three serologic groups was obtained.
The value of these studies had been a continuing evaluation to determine the significance of the presence of microorganisms in respiratory diseases, especially influenza, when characteristic association is expected. In the event of an upsurge of these bacteria, the availability of a diagnostic center seemed essential to maintain a state of preparedness. Support of the work was discontinued on 30 June 1945.
At the first meeting of the Executive Committee of the Commission in April 1941, Drs. Robertson and Dingle agreed to review the available investigations concerning masks designed to prevent dissemination of respiratory discharges. They obtained advice and recommendations from Drs. Charles K. McKhann of Harvard University, Cambridge, Massachusetts, and M. W. Jennison of the Massachusetts Institute of Technology (MIT), Cambridge. The latter recommended a gauze-covered mask with a Canton flannel filler and a flexible nose band. In September 1942, it was suggested that a conference be held to include those investigators actively engaged in the study of masks.
A meeting held 26 September 1942 was attended by the following persons:
Dr. Thomas Francis, Jr.
Dr. Charles K. McKhann
Dr. Deryl Hart
Dr. Ronald Rooks
Dr. M. W. Jennison
Major A. P Long
Conference members agreed that the masks ordinarily worn were worthless and recommended use of the type shown by extensive physical and bacteriological studies to be most effective. Specifications were formulated by Dr. McKhann and approved by other members of the conference. The report of the conference was transmitted to the President of the Board on 10 October 1942.
CHEMOTHERAPEUTIC STUDIES OF EXPERIMENTAL, COMBINED BACTERIAL, AND INFLUENZA VIRUS PNEUMONIA
At Washington University, beginning in 1943, Dr. Barry Wood assisted by Dr. Carl Harford initiated studies on the influence of sulfonamides in pneumonia in which influenza virus was associated with type I Pneumococcus or hemolytic Streptococcus in animals.35 The following observations were made: (a) In mice, even in the presence of subsequently fatal infection due to influenza virus, a concomitant bacterial invasion was eliminated by sulfonamide. (b) In rats, the bacterial component of a combined infection was also controlled. (c) In mice, the inhalation of finely dispersed type I pneumo-
cocci did not produce infection, but if the mice had been previously infected with a sublethal virus infection 5 days earlier, they died of a pneumococcal infection. The bacteria did not enhance the virus effect before treatment with sulfonamide brought about recovery.
They concluded that in the event of an epidemic of influenza, chemotherapeutic measures would probably aid in controlling pneumonia if a pneumococcal infection was superimposed on an influenza viral infection. This coincided with a comment made by Drs. Eaton and Meiklejohn that of six instances of pneumonia that occurred in their unvaccinated controls of 1943, all responded promptly to sulfadiazine.
PENICILLIN IN STREPTOCOCCAL TONSILLITIS
In 1944 at Fort Jay Regional Hospital, Governor's Island, New York, Dr. Plummer and his associates showed that in severe tonsillitis caused by Streptococcus hemolyticus, continued treatment with 15,000 units of penicillin given intramuscularly every 4 hours promptly produced negative throat cultures. However, discontinuation of treatment within 6 days resulted in relapse and return of infection. With longer treatment, pharyngeal cultures remained negative.36 The study emphasized the dangers in casual treatment of acute streptococcal infections of the throat.
In 1945, Dr. Eaton reported a study of the effects of some 60 compounds, unrelated to sulfonamides, on viruses of the psittacosis group. All results were negative. It was shown in certain species of animals that a drug might show some activity against a given virus, but against the same virus it would have no effect in a different animal species. This was an interesting observation. Chemotherapy of influenza virus infections showed no progress, which emphasized the need for further exploration using different methods.37
Investigation of Postvaccination Jaundice at Chanute Field, Jefferson Barracks, Scott Field, and Fort Sheridan-12-20 April 1942
On 12 April 1942, Dr. McKhann of the Commission on Measles and Mumps and Dr. Francis of the Commission on Influenza undertook an investigation of jaundice, which was occurring at Army camps. At each installation, clinical and epidemiological studies were conducted and specimens were obtained for investigation in the laboratory of the Commission of Influenza in Michigan. As data on icteric patients were assembled at Chanute Field, Illinois, it became apparent there that the most prominent common factor was the prior vaccination with yellow fever vaccine, lot no. 335. The incubation period in 80% of the cases varied from 62 to 84 days. Lack of contagious spread was clearly demonstrated. At Scott Field, Illinois, information was obtained from additional personnel vaccinated with lot no. 335. Ten thousand men at that post who were vaccinated with other lots were not infected. The results
indicated that in this area, that yellow fever vaccine lot no. 335 was seriously implicated. The incidence of hepatitis in vaccinees was 10% to 15%. There were a few instances in which other lots were indicated, such as lot nos. 338, 351, 334, and possibly a few others. At this time it was learned that lot no. 368 had been used at Fort Sheridan, Illinois, at the end of February 1942 without any recognizable effect by April. Attention was called to the fact that the resulting illness was severely incapacitating and that sequelae were anticipated. The disease was clinically comparable to that ordinarily called catarrhal jaundice. In view of the extended incubation period, comments were made regarding pathogenesis of the disease and whether it might be due to yellow fever virus or to an extraneous agent accidentally incorporated in the vaccine. The report suggested that a commission be organized to study the biochemistry, treatment, and prognosis of the disease.17
Fort Custer-4 and 5 June 1942
Dr. Francis also investigated the same illness at Fort Custer.17 At that time there were 212 cases of jaundice, which increased to a total of 650 cases by the end of July 1942. Yellow fever vaccine lot no. 368 appeared to be responsible for all the cases. It was the same lot that had been used at Fort Sheridan, where no cases had been detected within 2 months after vaccination. The illness at Fort Custer seemed less severe than that observed earlier in the spring and the incubation period was most commonly 90 to 100 days. Urticaria was observed to occur in a certain number of persons 1 or 2 weeks before onset of signs of acute hepatitis. A group of officers of the 12th General Hospital, then located at the post, were interested in conducting an extensive study of the disease and recommended that the Commission on Influenza conduct these studies. As a result, a committee was appointed by the Commanding Officer with Lieutenant Colonel N. H. Barker as President. In their studies, the committee emphasized the frequency of non-icteric cases with apparently similar disturbances and the adverse effect of exercise upon patients who were at this stage of illness or who were in the early stage of convalescence. Further attempts were made at the University of Michigan laboratory to establish an etiologic agent. The excellent report to the Board included a large number of determinations of liver function tests, effect of exercise and therapy, and a description of relapses. This report was submitted to The Surgeon General's Office late in 1942 and represented a major contribution of new knowledge regarding hepatitis.
The differentiation between infectious hepatitis and what is now known as serum hepatitis was clarified by Dr. Francis, who spent approximately 6 weeks in Sicily and Italy at the invitation of the Surgeon of Natousa (North Africa theater of operations) and his colleagues in the Armed Services. After considering many possibilities, they noted a correlation among the occurrence of hepatitis, malaria, and dysentery. They also noted a relationship between traumatic injuries and blood transfusion to transmission of the agent but obtained no supporting data to support this concept. Insect transmission was also considered. Dr. Francis collected a number of specimens, particularly blood, which were transported to Ann Arbor for further study. A full report was made to The Surgeon General, Department of the Army.17
CLINICAL INVESTIGATION WITH MATERIALS FROM NATOUSA
In the summer of 1944, arrangements were made for volunteers from the state prison at Dearborn, Michigan, to participate in experimental studies involving the sera and tissue specimens obtained in North Africa. Captain A. W. Frisch, an experienced microbiologist, was reassigned from Camp Custer to work at the Commission's laboratory in Ann Arbor and to assist in these studies.
Four volunteers received a filtered dilution of serum subcutaneously from a patient taken 7 days after the onset of symptoms. Four other persons were given a 20% suspension of filtered feces orally from the same patient. Four volunteers were given 1 mL of serum subcutaneously taken from a patient 3 days after the onset of jaundice. Four volunteers received the same amount of the similar serum that they gargled and swallowed. No jaundice occurred.
On 13 April 1945, a study was carried out using mosquitoes that had fed on the same patient and were killed at various times after feeding on the patient. The mosquitoes had been allowed to feed for 1 day after the onset of symptoms. Five were sacrificed after 1 day of feeding and the others 8 days after feeding. A suspension was made of a pool of mosquitoes and injected into four volunteers subcutaneously. No jaundice resulted in any of the recipients.
In May 1944, serum was obtained from an apparently well soldier who had served as a donor to a man who was recovering from a gunshot wound. Two days later the donor reported to sick call with icterus. The disease developed rapidly and he died 5 days after serving as donor. The recipient had his first suggestive symptoms of hepatitis 11 days after the transfusion. After 19 days his liver edge was palpable and tender. More definite systemic symptoms, including fever, were noted on the 20th day, and jaundice was first detected on the 21st day after transfusion. Samples of serum were taken 8 days after transfusion (13 days before the onset of jaundice) and also 14 days after transfusion (7 days before the appearance of jaundice). On 13 April 1945, four men received subcutaneously 1 mL of the filtrate from the first sample of serum and another four men received 1 ml, of the filtrate of the second sample. Thirty-eight days after inoculation of the first group, one of the patients became ill. Jaundice developed on the 41st day and the patient died on the 46th day. The second subject developed symptoms on the 39th day, jaundice on the 44th day, and a relatively mild, uneventful course of hepatitis thereafter. The third subject had onset of symptoms on the 44th day, jaundice on the 49th day, and a moderately severe illness afterward. The fourth subject had intermittent symptoms from 21st to the 41st day without evidence of jaundice or hepatitis detectable by biochemical tests.
In the second group, one volunteer had onset of symptoms on the 43rd day and jaundice on the 47th day followed by a moderate illness and uneventful recovery. The other three subjects had intermittent periods of digestive disturbance, but no jaundice was noted over a period of 135 days.
The experiments were useful but inconclusive in solving the problems of hepatitis. It became obvious that the limitations in the use of human subjects was such that only very vital questions dealing with the problem should be investigated in this manner. Other specific tests useful for detection of virus or the mechanisms of its action must be sought.
No further studies were performed in volunteers because World War II came to an end and Captain Frisch was demobilized.
At the laboratory of the Commission on Influenza in Ann Arbor, Michigan, studies of hepatitis were carried out with the aim to induce the disease in experimental animals. This was performed with material taken from 14 acutely ill patients and 5 fatal cases. The materials included stool specimens,
defibrinated blood serum, duodenal drainage fluid, liver sections, and suspension of duodenal wall. Monkeys, lambs, pigs, cats, rabbits, guinea pigs, ferrets, mice, eggs, chicks, and chickens were utilized in the studies. Presumably infected tissue was introduced by feeding and by the intravenous, intracerebral, intraperitoneal, intrahepatic, and subcutaneous routes. In all instances animals were kept under observation for at least 4 months. There was no further opportunity for testing the presence of virus in human subjects.
Throughout this period Dr. Francis enjoyed excellent working relationships with Board members, with practically all civilian workers in the field, and with his military counterparts, who respected him greatly not only for his skills as an epidemiologist but his ability as a clinician. He maintained a continuous interest in clinical affairs and was a fine physician. His reports always generously acknowledged the help of many individual contributors during the war years. Under his leadership, the Commission answered numerous questions that came to it from multiple sources.
ALERT FOR INFLUENZA
While the vaccination program was under development, there were continuous efforts to become aware of early prevalence of influenza. The weekly incidence reports of respiratory diseases made it possible to note trends or sudden changes, but it was impossible to investigate all potential threats. Various members of the Commission, through their continued association with military posts in their respective areas, were able to obtain estimates of the character of current respiratory diseases. This was particularly true of Dr. Eaton in California, who was freely called upon by the Ninth Service Command. Similar responses by Michigan laboratory personnel involved repeated trips to Fort Custer, a large base in Michigan, where special examination of materials obtained from other areas was performed. Dr. Hirst also made repeated tests in civilians and at certain Army bases in the New York area. At the bases where vaccination studies were in progress, there were continuous efforts to identify the presence of influenza. Despite all these efforts during the last 6 months of 1941 and throughout 1942, there was no evidence of influenza A or B except for a few positive serum tests for influenza A found by Dr. Eaton at Camp Roberts, California, in February 1942.
In early 1943 influenza B was detected in Michigan in several civilian groups and at Fort Custer. At the Eloise Hospital, Eloise, Michigan, a study of vaccination was in progress and examination of sera suggested that an incidence of influenza B of nearly 20% of the complement had occurred among the 2,900 unvaccinated controls. In spite of this, clinical illness was infrequent, although two instances of influenza A were suggested by the serologic tests. There was widespread infection so mild that it was rarely detected clinically despite intensive efforts to record all cases of respiratory disease regardless of their character. Influenza B was again identified in May 1943.17
Influenza A was identified in Michigan and found to be of the same type as previously isolated from an outbreak among a group of interns in New York City in April. Influenza A was also identified at Fort Custer. These observations clearly demonstrated an important, previously unidentified fact regarding influenza, namely, the occurrence of widespread patchy distribution recognized only because of the constant support and vigilance of several diagnostic laboratories. Influenza A had previously been considered to be an epidemic disease of varying severity, but evidence of its sporadic, not epidemic, nature was established.
To intensify the active alert, members of the Commission initiated a program of detection with the following assignments: Dr. Hirst and the Commission on Acute Respiratory Diseases, Second and Third Service Commands; Dr. Buddingh, Fourth Service Command; Dr. Francis and Dr. Salk, Sixth Service Command; Dr. Rickard, Sixth and much of the Seventh Service Command; Dr. Hale, Seventh Service Command; and Dr. Eaton, Ninth Service Command. From May to November 1943, no cases of influenza A were detected. In November, influenza A was detected in Michigan, Minneapolis, and St. Louis, Missouri, where other studies on influenza were in progress. Within a matter of days this information was transmitted to all other groups. The early identification of this epidemic was very helpful in evaluation of the effect of vaccine because all cases could be identified. In 1944, the sampling was augmented by Dr. Magill in the First and Second Service Commands and by Drs. Wood and Harford in the Seventh Service Command. No outbreaks of influenza A were detected up to the end of April 1945.
The effectiveness of the committee organized for the detection of influenza was well demonstrated during 1945. During the rest of that year members of the Commission or their affiliated units identified 16 outbreaks of influenza B of varying magnitude. Most of these episodes were small but some sharp outbreaks affected civilians as well as military personnel. Large numbers of cases were observed in Hawaii, and an outbreak of influenza B occurred in students at Yale University at the end of the year. It was reported by Dr. Blake and the virus identified by Dr. Hirst. Dr. Francis learned of overseas outbreaks on Tarawa, Guam, and Saipan. On Tarawa, it was said 83% of natives were affected, but there was little infection among caucasians.
The Commission members derived great satisfaction from visiting Army laboratories and observing efforts to acquire information quickly. In many instances, because of previous experience with Commission members, each visit was welcomed. It served to stimulate interest in the entire field of communicable diseases. Without these cooperative activities in spatial and temporal relationships, a long and drawn out incidence of influenza B of such mild and irregular distribution might have been overlooked. The Commission, through these procedures, maintained a broad picture of the patterns of illness and brought into perspective numerous isolated occurrences that formed a composite epidemiological picture. This enabled the Commission to advise the Army effectively and accurately as to the most desirable technical control measures. The experience seemed to reinforce the impracticality of waiting until an epidemic began to institute prophylactic vaccination. In nearly every instance mentioned in the report, the peak had been reached before the investigation succeeded in identifying the cause of the disease. The data obtained in the 1943 episode showed clearly that vaccination should be carried out before the virus made its appearance. As a result, data of great value were obtained.
THE COMMISSION-1946 TO 1950
Continuation of the Commissions
When World War II ended, the question arose as to whether the AFEB would continue to function as it had during the war. Use of the Commission structure had been highly successful in field investigations of infectious diseases, and such activities continued to provide protection to the Armed Services against a variety of diseases. The Commissions had already made substantial progress in many areas. Furthermore, it was obvious that the demobilization of the Armed Services would by no means be complete and that the draft would continue for an indefinite period. In view of the uncertainty of the world situation, it was anticipated that a substantial number of recruits would enter military service during the coming years.
Research on influenza had progressed considerably toward achievement of the goals that the Commission had established. A number of experiences made it patently clear that many problems needed
considerable more study before solutions were reached. Commission members had taken part in a number of studies at military installations. Generally, they had learned how to work well with their colleagues in the Armed Services. A concern that the Commission system might be abolished prompted a decision by Dr. Francis to prepare a history of the Commission on Influenza during the World War II period. It was with considerable relief that Commission members learned that their activities would continue, at least for a while. Some of the most important lessons learned up to that time were that behavior of the influenza virus was extremely difficult to predict, many older notions had to be discarded, and new problems would appear almost every year. All of these potential problems would require study and solutions.
1946 and 1947
Influenza B had not been detected since 1940 except in 1943 when a few scattered cases were encountered in Michigan. In 1945, however, the disease was identified as having caused outbreaks in practically all parts of the country as well as in Alaska and Australia. The alert system established earlier had functioned extremely well; laboratory data sufficient to identify the cause of the disease were obtained during most outbreaks. An extensive outbreak among civilians on Oahu, in the territory of Hawaii, led the Theater Surgeon to request aid from the Commission on Influenza. Captain Hirst and Dr. Francis left their posts on 27 June 1945 to investigate the outbreak. The number of civilians reported ill during that time was approximately 7,000. The number of admissions for respiratory disease in the Army totaled 2,600 between 1 June and 18 July. Vaccine had been administered to medical personnel, but the illness was so mild that there appeared to be no need for general vaccination. Drs. Francis and Hirst proceeded to Saipan and Guam where they found an increased incidence of respiratory infection identified by workers at NAMRU 2, on Guam, as influenza B. They subsequently obtained information that the Eighteenth Medical Laboratory on Okinawa had identified influenza B and also that it had information regarding another outbreak on Leyte, Philippine Islands. Dr. Salk visited Germany to establish diagnostic outposts in Army laboratories in the European theater.
In July 1945, Dr. Eaton identified influenza B in troops who became ill aboard a ship that had just arrived from the Pacific; a small local outbreak occurred in Stockton, California. Thereafter, in late August, outbreaks occurred at Fort Hood, Texas, Fort Dix, New Jersey, and at Fort Bragg, North Carolina. By November the illness was very widespread and was detected across the United States. Information from Australian workers indicated that this was the first time in their experience that influenza B was responsible for a large general epidemic.39 Thus, it was demonstrated that influenza B, which had behaved like an endemic disease, had attained epidemic characteristics and caused sharp epidemics in specialized segments of the population.
Influenza A was not noted during most of the time that influenza B was prevalent. However, there were scattered cases of influenza A detected in the Fourth Medical Laboratory; this supported the belief that influenza A had occurred in 1945 and suggested the possibility that the current cases were forerunners of a more extensive epidemic in autumn of 1946.
Effectiveness of Vaccine Against Epidemic Influenza B
There was no system similar to that which had been used in 1943 available to demonstrate the effectiveness of vaccine against influenza A. However, several observations were made that indicated that the influenza B component of the vaccine was effective, possibly more so than the A component. None of these observations was as well controlled as the 1943 study. At the University of Michigan, the comparison of the attack rates in a small number of vaccinated Army personnel compared with unvaccinated Navy students showed a hospitalization rate of 1.15 in the vaccinated Army group and 9.91 in the Navy group, which was unvaccinated. At Yale University in Army and Navy student training units, Dr. Blake requested that Dr. Hirst visit the infirmary on November 19. The situation there was slightly better controlled. All persons with temperature levels of 100°F or more who could not attend classes had to visit the infirmary. Vaccine coverage was good for Army personnel. Navy personnel were not vaccinated. Obviously, many people failed to report to sick call.
Dr. Orville Rogers at the Yale University Department of Health, with the aid of Dr. Frederick C. Robbins, attempted to separate the cases into the following categories: (a) Influenza with typical picture; (b) influenza complications, indicating typical influenza followed by some other disorder such as otitis media; (c) influenza, questionable; (d) URTI, upper respiratory tract infection noninfluenzal. In each of these groups there was a heavy preponderance of cases in the Navy group compared with Army personnel. The difference in rates was 16.9% in unvaccinated and 1.9% (vaccine efficacy 89%) in vaccinated subjects. This showed obvious protection afforded by the vaccine.40 The study also pointed to the effectiveness of vaccine given before an epidemic occurred and the value of an "alert system" that was organized to provide information on the prevalence of influenza B throughout the general population. Also, it was shown that influenza B, as well as influenza A, could be prevented by use of inactivated vaccine. This experience provided more valuable data obtained by the cooperative work of the Commission on Influenza control program.
Studies on Influenza Vaccines
Dr. Stanley studied the influence of various chemical agents on the stability of centrifuged vaccines.40 Vaccine at a concentration of 1 mg/mL, when held at pH 7.6 and 4°C, showed a marked loss in agglutinating activity. The virus had been formalinized, in different concentrations, with buffers at pH 7.0 with no loss of titer at 4°C at 30 weeks. Virus treated with concentrations of Formalin of 1:640 and 1:570 also showed considerable loss of titer at 4°C. There was no loss at concentrations of 1:2000.
Dr. Salk showed that the stability of the virus in allantoic fluid exposed to temperatures between 56 and 65°C varied considerably from strain to strain. The Weiss strain (1943) was destroyed in 1.5 hours, the PR strain in 6 hours, whereas the B/Lee strain was stable for at least 10 hours but was destroyed in 24 to 36 hours.
Tests by Dr. Hirst showed that there was no difference between the antibody levels of persons who had been vaccinated with either Commission-provided vaccine or vaccine prepared by Sharples cen-
trifugation at intervals of 2 weeks, 18 weeks, and 14 months after vaccination. Most vaccinees showed titers higher than their original level.41
Dr. Salk also compared the antibody levels at the end of the year of a group vaccinated with double-cycle centrifuged vaccine in amounts of 0.1 mg to 2.0 mg and compared with eluate vaccine prepared in 1943.42 The best results were obtained with the 2.0 mg material. The differences were evident when measured against B/Lee, but less distinct against the type A viruses. There was no evidence that centrifuged vaccine, because of its purity, was superior antigenically to the eluate material except when the doses were increased beyond a practical level.
The results of the two studies established the fact that there was no standardized method for measuring HI antibodies. Dr. Salk continued to determine the possibility of increasing the potency of influenza vaccine by absorption to calcium phosphate. When influenza virus was absorbed to calcium phosphate, there was an increase in titer 2 weeks after vaccination. No data were obtained on persistence of antibody 1 year after vaccination.
Protective Effect of Vaccination in Swine
Dr. Beard and his associates continued to test the degree of immunity to induced infection after subcutaneous or intranasal vaccination of swine influenza virus in hogs.43 Those animals that received vaccine subcutaneously appeared somewhat more resistant than those that were unvaccinated. This effect was most marked in those vaccinated three times before infection. All vaccinated animals showed sharp antibody rises after the intranasal administration of active virus. Animals that had recovered from intranasal infection showed a more complete and uniform resistance than any of the vaccinated groups. Some animals were revaccinated after 13 weeks and then rechallenged a month later. One fourth of the animals showed mild clinical infection randomly distributed between vaccinated and revaccinated animals. There was no evidence that revaccination enhanced the resistance of the recovered animals, although a further antibody increase took place. Dr. Beard and his colleagues next investigated the effect of combined intranasal and subcutaneous vaccination. Subsequent exposure to intranasal virus did not cause typical infection.
It appeared that antibody titers had an inverse relationship to clinical response to infection. In general, the results did correspond with those obtained in ferrets, demonstrating that subcutaneous vaccine did not produce a consistent solid immunity to infection.
Intranasal Vaccination in Humans and Ferrets
Dr. Francis and Dr. Joseph Quilligan investigated the effectiveness of an intranasal spray of inactivated vaccine on antibody response of children 8 to 12 years of age.44 They found that a single spray produced a modest antibody response that was considerably increased when the spray was administered five times. After intranasal vaccination, the mean titer was less than one-half that following subcutaneous vaccination.
Intranasal spraying of vaccine in ferrets uniformly produced antibodies in all animals. However, all were susceptible to both influenza A and B viruses despite the antibody production.
Dr. Jonas Salk, a New Yorker, received his medical degree from New York University in 1939. This was followed by internship at the Sinai Hospital from 1940 to 1942. He was attracted to the University of Michigan School of Public Health, Ann Arbor, by Dr. Thomas Francis, where he progressed through the ranks between 1942 and 1947 as fellow, research fellow of epidemiology, to associate professor of epidemiology. Here, during the war years, he worked closely with Dr. Francis and participated actively, with AFEB support and collaboration, pursuing and adding new important knowledge to the fields of influenza, pneumonia, related respiratory infections, and vaccine development. This outstanding work was conducted in the laboratory and in various U.S. military field sites throughout the country and abroad. Dr. Salk moved in 1947 to the University of Pittsburgh School of Medicine, where he directed the virus research laboratory and painstakingly developed the inactivated poliomyelitis vaccine. This was a contribution of immeasurable significance that has assured him lasting national and international recognition.
Strain Study Center
Drs. Magill and J. V. Sugg accepted the responsibility for rapid development of a center to identify influenza strains for the Army and for other laboratories where such facilities were lacking. Hyperimmune sera had been prepared. Sera were obtained from persons vaccinated during the 1943 and 1944 trials and then tested against various strains to determine the important antigenic differences. Similar data were obtained from ferrets.
The data showed that the differences among strains presented a fundamental problem that could not be ignored. The collection of strains had been continued. In addition to virus strains submitted by the various members of the Commission and associates in the United States, a large number of strains were received from Dr. Christopher Andrewes in England. There was no suitable method of systematic classification, and it was very difficult to predict the relationship of one strain to another. The question of whether a strain would be a good antigen had not been solved. The most feasible plan appeared to include standard strains such as WS and PR/8 and also several strains from recent epidemics. The latter should be derived from widely separated localities rather than from a single place.
Toxicity of Influenza Virus
Dr. Hale from the University of Iowa concerned himself with studies on mechanisms of toxicity and worked with a type B virus isolated on 19 November. Small amounts of this strain killed mice in 48 to 72 hours after intranasal inoculation and produced the same type of destruction of the respiratory epithelium as that produced by mouse-adapted virus.45
Dr. Francis and Dr. Salk began a study of the comparative effect of repeated doses of influenza virus given for five doses on alternate days, the effect of vaccine given every 2 weeks for five doses, and the effect of a single large dose. They also investigated an inhibitor found in allantoic fluid of newly isolated virus strains.
Vaccine obtained from Army stock supply was given to a large number of students and personnel at the University of Michigan. The vaccine appeared not to have lost potency and produced a satisfactory antibody response in a number of individuals. To determine the frequency of adverse reactions, 370 residents of girls' dormitories were carefully followed after vaccination. Four (1.1%) had fever of 100°F the following day, and nine (3.2%) others complained of malaise without evaluation of temperature. The mildness of these reactions was fairly surprising.
Early in March 1947, an increased number of respiratory illnesses occurred in Michigan. During the first part of the epidemic there was a high incidence of nausea, vomiting, and diarrhea in certain groups. Other cases appeared more characteristic of influenza. It seemed likely, on a clinical basis, that at least two different diseases were present. Attempts to isolate virus by egg inoculation were unsuccessful. Three strains were isolated in ferrets. They were type Abut quite distinct from standard strains.
Other Field Investigations
Dr. Salk investigated an outbreak of respiratory disease at Chanute Field and Scott Field in Illinois during the last week of February 1947. The disease was characteristic of mild influenza. One of five
George Hirst, a distinguished scientific product of the Rockefeller Institute, worked collaboratively with Frank Horsfall, Ed Kilbourne, and many others who contributed so importantly to our knowledge of influenza. His seminal discovery in 1941 was demonstration of the agglutination of erythrocytes by the influenza virus and that the elution reaction following hemagglutination was mediated by enzymes and that the neuraminidase enzyme was an important part of the virus molecule.
His work, with associates, on genetic manipulation of influenza viruses provided the basis for construction of better vaccines. Among his many accomplishments was editorship of the Journal of Virology (1955) and directorship of the Public Health Research Institute of the city of New York (1956). The Commission on Influenza of the AFEB was enriched by his contributions.
throat washings yielded a virus by egg inoculation. Type A virus was identified. The interesting observation was made that the disease had a much higher attack rate in students than in the permanent personnel. A like observation was subsequently made at Scott Field, where a similar illness occurred almost simultaneously with the administration of vaccine. The serologic (HI) tests did not distinguish cases of influenza from the response to vaccines.
During an outbreak of typical influenza, Dr. Hale at the University of Iowa inoculated throat washings from 15 patients into eggs. He used both amniotic and allantoic routes and multiple passages of each specimen. No virus had been isolated up to this point. Convalescent sera had not shown a rise in antibody against virus type A or B.
Dr. Hirst in New York isolated a number of strains of influenza A. The strains were difficult to identify by serologic tests. The outbreak was not sharp, but appeared to be low grade and long continued. One strain was isolated from the Army personnel at Fort Monmouth, New Jersey (FM-1). Dr. Magill in New York received no materials from Army hospitals. Throat washings from civilians were tested but none were positive. Dr. Eaton in California reported that influenza had been recognized in January, and identification of virus was made by the Army laboratory personnel at Monterey. Cases of influenza appeared among several civilian populations in northern California.
Dr. Harold Diehl at the University of Minnesota investigated the effect of influenza vaccine against the common cold. No favorable protective effect was demonstrated.46
1947 and 1948
Following an epidemic of mild influenza in the early months of 1947, numerous laboratory groups isolated strains of influenza A virus and studied the serologic responses of patients. It was clearly established that the virus was related to type A but was serologically distinct from the strains such as PR/8, which was contained in the vaccine. In addition, observers noticed that the vaccine provided poor protection against the new virus strains. These strains were more difficult to isolate in eggs, adapt to good growth in the allantoic sac, and adapt to mice. Serologic tests were difficult to evaluate because of the high inhibitory effect similar to that observed in 1945 with the new strains of influenza B. It was suggested that the group be called "A-prime" (H1N1). During the remainder of the year strains of influenza A-prime were isolated in a number of areas, but no epidemic occurred until November. A sharp rise in cases was recognized in California with an incidence comparable to that in early 1947. Influenza A virus circulated for a full year, with behavior similar to influenza B in 1945.
At the annual meeting of the AFEB in May 1947, it was recommended that (a) influenza vaccine be used throughout the Army in the autumn of 1947; (b) the FM-1 strain of the 1947 variety (A-prime) be incorporated into the vaccine; and (c) controlled studies be made on a continuing basis for the evaluation of influenza vaccine in the Army.
Because of the short time interval, most pharmaceutical companies were reluctant to provide vaccine. The contract was finally made with Lederle Laboratories for the preparation of vaccine by centrifugation. The delivery of this vaccine was delayed because of production difficulties.
Tests of these vaccines in humans suggested that the material was not as effective as might have been anticipated and was less effective than older material that was on hand. It was suggested that the FM-1 strain was not as stable as PR/8 and that the antibody response to the A-prime strain was not as high as against other type A strains. The stability and behavior of these A/prime viruses remained a problem.
A large study comparing the rates of illness in vaccinated and unvaccinated individuals was undertaken at the University of Michigan. In this study involving 17,000 vaccinees, the results clearly showed failure of the prophylactic effect of vaccination.
Because the recommendation had already been approved to vaccinate all Army personnel in the fall, a problem had been created because testing controlled by use of placebo could not be done. It seemed feasible, however, to compare the value of the "old" vaccine containing the PR/8 virus and the "new" vaccine containing equal amounts of FM-1 and PR/8 as one-half of the A component. Approval for such a study was obtained from The Surgeon General's Office and the study was begun 14 November 1947 by Dr. Salk at Fort Dix. Another study designed to evaluate vaccine and compare attack rates on vaccinated Army personnel was arranged at Fort Belvoir, Virginia, and the Marine Base at Quantico, Virginia, where vaccine was not to be given (control group).
The ad hoc committee appointed by the Board to plan for these studies consisted of Drs. Francis, Dingle, and Joseph Smadel together with Drs. Salk and MacLeod, Lieutenant Colonels Robert Bauer and Arthur Long, and Colonel Thomas Whayne. It met again on 15 March 1948. There had been no peak of influenza A during the previous season, and the great bulk of illnesses occurred on the west coast. Dr. Meiklejohn reviewed the prevalence in California and pointed out that the incidence was about the same as the previous year and that the strains were antigenically similar. Dr. Salk had encountered difficulties in his field studies because Army personnel specifically assigned to assist in the work were not available at the installations.
The Committee did not recommend uniform vaccination for the coming year; it suggested that reasonable stockpiles of vaccine containing type A, A-prime, and B be prepared. The Committee recommended that (a) a controlled evaluation in the Army be conducted in the coming year, especially in view of the experience with the A-prime strains that were encountered over the previous 2 years; (b) a controlled study be conducted at Fort Dix employing monovalent A, A-prime, and B vaccines in the same units; (c) the study at Ft. Belvoir and Quantico be continued if conditions were advantageous; and (d) the situation at Fort Ord be explored by Dr. Meiklejohn with a view to conducting a study similar to that at Fort Dix. The Committee formulated a number of specifications for the new vaccine and considered that its ad hoc functions had been fulfilled.
Strain Study Center
The Strain Study Center that had been maintained by Dr. Magill was reactivated and expanded. Efforts were being made to obtain standard sera and to follow standard procedures. The committee of Drs. Magill, Feller, Ross Gauld, and Salk were asked to confer about the adoption of a procedure as a standard of reference for HI tests. The facilities of the Center were offered for cooperation with the World Health Organization's (WHO) plan to establish listening posts like those that the Commission had maintained for 6 years. It seemed likely that this Center would be the major center for the Americas.
To determine the effect of repeated inoculation of one strain of virus on the breadth of the antibody response to strains of different degrees of relationship, groups of children (average age 3.2 years) were given vaccine in various doses and at various intervals. It was found, in general, that children over 4
years had probably been previously infected and produced their maximum response after their first dose of vaccine. Titers changed little with subsequent doses. Children under age 3 years behaved somewhat differently and reached their maximum titer after the third dose and did not increase thereafter. The study showed that children may not produce the broader heterologous response of the type observed in experimental animals such as the ferret. It also showed that when children were given small dosages, more than one dose should be given.47
Dr. Salk obtained evidence that intramuscular injection of virus might produce a better antibody response than the usual procedure of subcutaneous injection. In association with Dr. Dionyz Blaskovic, he also obtained data that indicated that the HI antibody and virus neutralizing antibody were separate entities as measured in the egg neutralization tests.48 He continued his studies on potency tests of vaccines.
Dr. Meiklejohn reported from California that there had been a moderately widespread incidence of influenza A-prime starting in the southern part of the state. A-prime viruses had been isolated from 8 of 11 separate throat washings following amniotic inoculation of chick embryos. The first passage of the virus showed hemagglutination with only one of the seven strains, but all of the viruses agglutinated red blood cells readily in the second passage.49 In comparing the results of HI and complement fixation tests on 40 serum pairs from early 1947 and 90 pairs from 1947 and 1948, it was found that only 64% developed a significant increase in HI titer to the PR/8 strain. The complement fixation tests appeared to have been the most useful single diagnostic procedure.
Following through on recommendations of the special committee on A-prime strains, contact was made with Colonel Alvin L. Gorby, Sixth Army Surgeon at Fort Ord, and with Colonel Francis E. Council, also of the Sixth Army Medical Laboratory. This was with the aim to arrange a study at Fort Ord analogous to the one conducted at Fort Dix. It appeared probable that satisfactory arrangements could be made. A comparison of the administration of vaccine by the intradermal route and the subcutaneous route was carried out in three groups, one in children and two in adults.
Dr. Loosli compared the response to inoculations of 1 mL given subcutaneously and 0.1 mL intracutaneously against five virus strains. The intracutaneous method appeared to produce a response as satisfactory as the subcutaneous route when tested with PR/8 and Lee strains of virus, but not with the A-prime, the FM-1, and J-16 strains. The response to FM-1 was unsatisfactory with either method of vaccine administration.
1948 and 1949
Six years had passed since the last characteristic epidemic of influenza A and 4 years since the last sharp epidemic of influenza B. It appeared that widely held opinions on the epidemiology of influenza held in the past were inaccurate. In the first parts of 1947 and 1948, A-prime viruses were distributed widely. Influenza B was also present in Germany; in Australia a sharp outbreak of A-prime occurred early in the year, and later in the year an outbreak of influenza B. In Europe, influenza B occurred rather widely and in the United States both A-prime and influenza B were present throughout the year. Interestingly, in Germany during the period from 1948 to 1949, all three viruses were isolated, the most numerous isolates being influenza A-prime.
World Health Organization Program
During 1949, the program initiated by the WHO had been more definitely formulated. The members of the Commission (see list of members, next page) continued to try to detect influenza as they had since 1942. They also agreed to transmit information to the Information Center established by the Public Health Service. There was a strong conviction that the Commission on Influenza should retain its integrity and functions in relation to the AFEB. The Strain Study Center established by the Commission
at Cornell under Dr. Magill was transferred along with him to the Long Island College of Medicine. It was recommended and agreed that this would serve as the Strain Center of the WHO for the hemisphere. The Commission members agreed that, when consulted about matters such as selection of strains for the next year's vaccine for civilian use, the Commission would speak as a group rather than as individuals.
Members of the Commission-1948 to 1949
Dr. G. John Buddingh
Standardization of Procedures
A committee with Dr. Magill as Chairman and composed of Drs. Salk, Meiklejohn, Feller, and Gauld (of the Army Medical School) met to devise an HI test for the influenza virus to serve as a standard of reference for all the modifications used in different laboratories. The last meeting was held on 3 March 1949, in Ann Arbor, Michigan. It was recommended that both HI and complement fixation tests should be used for routine serologic diagnosis.
Dr. Oti in Japan provided a strain of A-prime virus isolated from swine in Korea. The virus was not neutralized by standard Swine 15 serum or by PR/8 serum. It was found, however, that the anti-Oti serum in the Michigan laboratory did neutralize that virus to some extent. It was felt that the antibody responses were essentially parallel to that observed with the A-prime strain Rhodes. The results suggested that either the strain was of human origin fortuitously isolated from swine or that a swine strain had become, prevalent in the human population.50
Strain variation was demonstrated by Dr. Cheng-i Wang, who studied two lines of the Rhodes A-prime virus. One had been isolated and maintained in eggs; the other was adapted to mice. When the strains were introduced into mice, it was shown that the mouse-adapted line multiplied rapidly so as to reach its peak in about 12 hours; hemagglutination titers developed later. The egg-adapted strain reached its peak in about 48 hours, and only a minimal titer of hemagglutinin developed. The results suggested that the strains in epidemics may be those that, by selection, can multiply most rapidly in the human host.
THE COMMISSION-1950 TO 1957
By 1950, the composition of the Commission had changed. The number of members remained relatively small. Dr. Lennette was made a member of the Commission when Dr. Meiklejohn left California to join the faculty of Medicine at the University of Colorado. The number of associate members was
For 32 years, Dr. Joseph Smadel was a physician and investigator whose contributions to medical science either saved or prolonged the lives of thousands of people. At the time of his death in 1963, Joe was recognized as one of the outstanding scientists of the mid-20th century. Expecting no reward, he performed research because he liked it, and his labors provided the essential bridge between the laboratory and the physician who cares for infected patients. One of his most satisfying experiences was the therapeutic triumph with chloramphenicol in the treatment of typhus and typhoid fevers, and the successful field trials that showed that this antibiotic effectively suppressed scrub typhus infection.
A major contributor to the Armed Forces Epidemiological Board, he organized and directed three of its Commissions: those on Immunization, Rickettsial Diseases, and Epidemic Hemorrhagic Fever; each of these Commissions bears the indelible Smadel mark. He was also a member of the Commissions on Epidemiological Survey, Virus Diseases, and Influenza, and his stabilizing influence during the developmental phases of the poliomyelitis vaccine trials contributed significantly to that success.
Joe had little patience for armchair philosophy, and he crusaded against shallow thinking. He demanded unswerving performance from his associates, who were expected to exercise good judgment and to adhere to his personal brand of integrity. He never allowed his personal burdens to interfere with his dedication to his work, and his enthusiasm sparked the enthusiasm of his associates. He worked intently and set an example for others.
increased considerably and included many investigators in the country involved in influenza research. In addition, representation from the Public Health Service (Dr. Bell) and the Navy (Commander John Seal) and from Canada (Dr. Henry van Rooyen) were invited to attend the meetings. It was generally accepted that influenza vaccine had been shown to prevent both influenzas A and B, but the results showed there was need for improvement in the vaccine at the level of protection and duration of immunity.
Work continued by members and associate members on the problems of improving the vaccine and developing a better understanding of the mysteries of influenza virus. Most of the laboratories associated with the Commission continued to identify viruses and to evaluate the antigenic composition of the strains. Requests for assistance from the Armed Services were infrequent, and the Commission no longer received direct information from any of the Services concerning influenza. The reports on respiratory disease rates in the Army usually contained information that was 3 to 4 weeks old. It appeared that the service laboratories had reached the stage of development that enabled them to function adequately on their own. In addition, the laboratories at WRAIR had developed rapidly under Dr. Smadel and Dr. Maurice Hilleman and regularly carried on their own activities at a top level. The Commission decided at its annual meeting to initiate a pattern of performance that was to continue throughout most of its existence.
The members and associate members met annually in Ann Arbor, Michigan, along with members of the preventive medicine branches of the three services. The meetings began with a report from each of the services on the status of influenza and of respiratory diseases in their respective services. These were followed by reports from members of the Commission or others directly concerned with vaccine studies and subsequent reports by all members of the Commission, associate members, and contractors who were engaged in other types of research. These were lively, delightful meetings that were moderated by Dr. Francis, who was a very effective leader for the meetings. He had a great regard for vigorous proof of any claims that were put forth and in a good natured way was able to distinguish between good and bad science. The meetings had a congenial character that was helped by the fact that the participants were all housed in the Michigan union, where they could get to know-the other participants well. The last evening was usually spent at Dr. Francis' house where the group again enjoyed a very friendly atmosphere. The relationships developed there lasted for many years. Dr. Francis, in the following years, assembled a very able and productive group of investigators in his department at Ann Arbor, Michigan. Dr. Salk came in 1941 as a National Research Council Fellow and remained until 1947, when he moved to the University of Pittsburgh. There he continued his adjuvant vaccine activities for a while and then shifted to the development of poliomyelitis vaccine. He stated that after trying to make a good influenza vaccine, it was very easy to make a vaccine for polio following the discovery by John Enders, Thomas Weller, and Robbins that polio virus could be grown in non-neural tissue.
After Dr. Salk's departure, Dr. Davenport was recruited, also from the Rockefeller Foundation. Dr. Davenport was an extremely dedicated person who worked very hard to move the program ahead. He also tried his best to maintain close relations with the Army medical personnel with somewhat dubious success. He was a very direct person, always honest and friendly. Other members of the staff included two pediatricians, Dr. Albert V Hennessy and Dr. Quilligan, who obtained much information on immunity to influenza viruses in children and defined most of the difficulties in immunizing young children.
Drs. P K. Brown and W. W. Ackerman, both basic scientists, were also valuable members of the team. Finally, Elva Minuse, the personal assistant of Dr. Francis, must be acknowledged. She had had long experience with influenza viruses and was thoroughly familiar with all procedures involved in isolating viruses and propagating them in eggs and mice. She was available to help any of the other investigators who worked with different laboratory procedures. It is of some historical interest that she had a major role in the isolation and adaptation of influenza B virus in mice.
The University of Michigan became the national center of influenza research. Among the investigators who became prominent in influenza research were the following: From the United States, Drs.
Keith Jensen, Gary Noble, Walter Dowdle, and William Marine. The first three of these subsequently went to the Centers for Disease Control, Atlanta, Georgia. Dr. R. Q. Robinson and Allan Kendal from England, Dr. Hideo Fukumi and several others from Japan, and Drs. Rob Webster and Fajekas van Groth from Australia all gained valuable experience at Ann Arbor, Michigan. The investigators at the laboratory remained in close contact with their British colleagues, who were under the direction of Dr. Christopher Andrewes.
Dr. Salk ceased his work with other possible adjuvants for influenza vaccine in favor of an adjuvant of mineral oil (Bayol F) and with Arlacel A (Freund's adjuvant without mycobacteria). The animal work had progressed well and he investigated the advantages of the adjuvant vaccine in humans. The same amount of virus in adjuvant produced far higher titers than aqueous vaccine; titers continued to rise for 6 weeks. At the end of the year, titers were far higher than they were for aqueous vaccine. One year after receiving vaccine containing 300 chicken cell agglutinating (CCA) units of virus, 90% to 96% of those who received the adjuvant vaccine showed titers of 256, compared with 28% with aqueous vaccine. Titers against the B-Lee and A-prime/Cuppett strains were lower than with earlier A strains.51
The dose of vaccine was studied in considerable detail.52 It was also shown that with a dose of 0.25 mL of adjuvant, as little as 10 CCA units of antigen would evoke an antibody response comparable to 300 CCA in aqueous vaccine. It was shown that when the volume of the material was increased from 0.25 to 1.0 mL of suspension, the antibody response was better with the larger volume. In terms of heterologous antibody, Dr. Salk demonstrated that the Cuppett strain in adjuvant produced a far broader heterologous antibody response than the same strain in the aqueous vaccine. It was also shown that the B-Lee strain of influenza (1940) produced a response parallel to the Warner virus (1948).
The prophylactic studies of adjuvant vaccine contained 500 CCA units per dose, considerably more than that used in any of the other vaccines. This amount of virus caused some local discomfort for 3 days in a number of persons. Furthermore, in 4,200 persons inoculated with the vaccine between 24 October and December 1951,17 (0.4%) developed subcutaneous fluctuant cystic swellings at the site of inoculation after 3 to 4 months. These swellings subsided after aspiration and were invariably sterile. They developed from the subcutaneous administration of the vaccine and appeared to be related to the lot of emulsifying material in the vaccine. Dr. S. H. Sell had observed 7 (0.2%) such incidents after vaccination of 3,000 persons with a similar vaccine.53
Dr. Hennessey at Michigan expanded studies to obtain information on the combination of influenza C virus with red cells.54 Dr. Frederick A. Rasmussen continued studies with the synthetic polypeptides and demonstrated that sequential blockade could actually be demonstrated in one system with influenza virus. His efforts to demonstrate recombination were unsuccessfu1.54
Dr. Loosli continued his studies of the effect of active and passive immunity in mice. His work with cortisone showed that mice tended to develop a spontaneous bacteremia from their own organisms. Cortisone was not found, however, to exhibit any influence on the antibody response to influenza virus, although after intraperitoneal inoculation of influenza virus, the agent persisted considerably longer and in larger amounts than in control animals.54
Parallel studies were conducted at Fort Ord and Fort Dix. Polyvalent aqueous vaccine containing PR/8, FM-1, and Cuppett strains of A and the Lee strain of B and a control vaccine of formalinized saline were given to equal numbers of volunteers. Influenza A-prime occurred in both areas in January, February, and March. A final summary of the results showed an approximately 4:1 (VE 75%) result in favor of the A vaccine in groups of essentially equal numbers.54,55
Dr. Edwin Lennette graduated from the University of Chicago, and was on the staff of the Rockefeller Institute at the same time as Dr. Monroe Eaton. He had worked on influenza while at the institute. He had been in charge of the viral encephalitis unit in Brazil. Almost all of his laboratory staff had been infected by airborn Venezuelan encephalitis virus, and he himself had been one of the victims. When Dr. Eaton moved to Harvard as associate professor, Dr. Lennette, was brought to Berkeley as his replacement. Dr. Lennette's interests in virology were very wide, and he soon developed diagnostic facilities at Berkeley that were probably unmatched in the country at the time.
He was highly active in discussions at meetings of the Commission. He liked to point out how frustrating it was to put in all the work and time in setting up field studies, and find that the disease that one was trying to prevent did not appear. This was an experience shared by other investigators who had set up studies on influenza or adenovirus disease in various parts of the country. In many years, either more, or only one or two, of the units had enough disease to provide significant results. After some time, his colleagues on the Commission developed what they called "Lennette's Law." "Lennette's Law" stated in essence "that it was impossible to evaluate a vaccine in the absence of the disease which the vaccine was supposed to prevent."
A study performed at the University of Michigan in an uncontrolled student population had failed to show any vaccine effectiveness. It is worth pointing out that both at Forts Dix and Ord, the number of cases was relatively small and was based only on patients admitted to the hospital. Presumably this was due to the fact that influenza A-prime produced only mild illness and did not require too many hospitalizations.
In two other studies at the University of Michigan, Dr. Francis obtained evidence that the vaccine reduced the incidence of influenza B. Captain Robert O. Peckinpaugh at Great Lakes Naval Training Center, Great Lakes, Michigan, also reported that Navy personnel experienced some influenza B, none of which occurred in persons who had received the B vaccine.
A study at Michigan that compared the antibody response of humans to mouse and egg lines of the same virus suggested that the mouse line was a better antigen in humans.54
Dr. Magill reported that an analysis of 100 strains of influenza virus from different years and different locations suggested to him that they represented five different subgroups of type A and four subgroups of type B. The groups seemed to be related to different time periods, and it was suggested that a relatively orderly progression was taking lace. The dominant antigens of the early strains were less likely to be encountered in recent strains.54 This interpretation was not universally accepted. There was a suggestion that the pattern was either recurrent or periodic. The studies were important in helping establish the antigenic constitution of the various strains and in providing information on the usefulness of the different components of future vaccines. Dr. Hirst, following the same lines of interest, used antibody absorption tests.
Dr. Keith Jensen at Michigan studied antibody absorption using the Oudin procedure of antibody migration in a semisolid medium to demonstrate the number of antigen-antibody reactions that could be detected.54
Drs. Magill and Beard undertook a study to establish methods to measure the relations of viruses to their biological activity, such as infectivity, agglutination, etc. There was, at that time, no proper reference standard. They suggested that the activity of the virus particle was related to the spheroid particles and that the filamentous forms did not interfere with potency determinations. It appeared that further studies were needed to clarify a number of points.54
Dr. Davenport conducted studies on adaptation of virus.56 When the viruses were used in diluted concentrations, adaptation appeared to be sharply retarded. These data suggested that the virus population becomes homogenous during passage. There was a definite correlation between the capacity to produce pulmonary lesions in mice and the concentration of virus as measured by hemagglutination. This was not true for infectivity in eggs. The mouse-adapted strain was less influenced by an inhibitor in normal mouse lung suspensions, indicating another capacity acquired by the virus during adaptation.
No one connected with a commission of the board was more faithful and persistent in his effort to reach the right conclusion than Dr. Fred Davenport. His former chief, Dr. Thomas Francis, passed the baton on influenza to Fred. Control by vaccine was under intense development as was the need to evolve a better understanding of the pathogenesis and epidemiology of influenza. He collaborated with the Commission as a member and directed its activities from 1955 to 1971. He was deliberate and thorough in all of his investigative studies, and the comments that he made during various meetings of the Commission and board were incisive. Michigan should be very proud of Fred Davenport and Tom Francis, who served the board and the public so effectively.
Dr. Harry Rose continued his investigation of a substance in human sputum that had a pronounced favorable effect on eggs infected with influenza viruses. The substance appeared to be a protein, very labile in character, and not a specific antibody. In eggs injected with 1,000 egg infective dose 50, the inhibitor reduced virus multiplication and delayed the death of the embryo. It appeared to have a limiting effect on multiplication of virus and a protective effect in the mice. He was attempting, at the time, to establish the nature of the material.
The Commission on Influenza met in Ann Arbor on 31 March and 1 April 1952. Attendees included Colonel Fratis L. Duff, Chief of Preventive Medicine of the U.S. Air Force, and Colonel Adam J. Rapalski, Executive Secretary of the AFEB, in addition to those listed in Appendix 3. The following recommendations were made: (a) Continued studies on the evaluation of influenza vaccine have consistently demonstrated that vaccine is effective in the prophylaxis of influenza caused by strains of virus prevalent in recent years. (b) It is essential that vaccination be carried out 2 weeks or more prior to an outbreak of an epidemic in an area. (c) There is no reason why vaccine should not be used uniformly if the avoidance of influenza is of sufficient importance. (d) The number of essential antigens is not known and a decision as to the most effective composition of vaccine is not possible at present. (e) Studies of influenza virus vaccine suspended in mineral oil (Bayol F) and in Arlacel A had shown great efficiency in stimulating extremely high and persistent levels of antibody. Furthermore, the amount of virus required was small. However, because of insufficient knowledge about those certain factors and occasional reactions of an undesirable nature, adjuvant vaccine should not be recommended for routine use. (f) The investigation of applicability should be continued under the direction of Dr. Salk.
There was further discussion of a number of points, such as the duration of resistance after vaccination and the stability of the vaccine. It was suggested that vaccine aged several years should be tested to determine its effectiveness in producing antibody. The possibility of conducting studies on Air Force bases such as Camp Sampson in New York state was also considered.
Dr. van Rooyen asked whether the Commission would make recommendations concerning the use of influenza vaccine for visitors within the Arctic Circle. The Commission thought this was an interesting problem, but the decision on such a matter was outside the jurisdiction of the Commission. At the conclusion of the meeting, Dr. Francis made the following notes about future plans:
No sharp shift of emphasis in studies has been planned for the coming year. The scope of activities is, at the present time, extremely broad and the extension of them in various directions will constitute a wide and diversified approach to the problem of influenza. It must be emphasized that in all activities the increased cost has been a serious item and the obtaining of personnel a continuing obstacle.
The last year of the A/H1N1 decade, 1957, was an unusually interesting one. An epidemic of influenza A-prime occurred in the Orient in November 1956 and later spread to the United States and Europe. The virus was identified at Great Lakes Naval Training Center, Great Lakes, Michigan, in December, and a sharp outbreak occurred at Lowry Air Force Base, Denver, Colorado, in January. By late January and February, influenza A-prime was reported from Washington, Michigan, Tennessee, California, Virginia, Arkansas, and New Jersey. The disease appeared to be mild but widely disseminated in many areas. The virus showed considerable antigenic drift from earlier A-prime strains, similar to those studied in 1956 by Dr. J. Mulder in the Netherlands. Influenza B was also present.
Dr. Meiklejohn reported that despite the considerable antigenic drift, aqueous vaccine containing 750 CCA units of strain A/Ann Arbor/56 provided a protection of 6:1 (vaccine efficacy 84%) in recruits.57 In seasoned (permanent party) troops, protection was considerably less apparent. The attack rate in the vaccinated persons was essentially the same as in the recruit population, but the attack rate in those not vaccinated was far lower, presumably due to the fact that the level of immunity was considerably higher. At Fort Dix the incidence was too low to permit an evaluation of protection.
THE COMMISSION-1957 TO 1961
In 1957 the Asian influenza virus appeared, first on the continent of Asia and subsequently around the whole world. This was by far the most damaging pandemic of influenza since 1918 and 1919. The virus, although still clearly an influenza A virus, had changed both its hemagglutinin and neuraminidase. The population at large had no HI antibody to this virus and was almost entirely vulnerable.
The virus was identified in the fall in the United States by Dr. Hilleman at the Respiratory Disease Division at the Walter Reed Army Institute of Research (WRAIR) and was confirmed by Dr. Keith Jensen at the Centers for Disease Control and at the Ann Arbor Virus Laboratory. The director of the Commission traveled to Australia, the Philippines, Japan, Hawaii, and to Santiago, Chile.
It soon became clear that vaccine would be in short supply at the time when the virus reached the various bases. A number of studies were performed comparing the effect of intradermal injection of 0.1 mL with that of an intramuscular dose of 1.0 mL. A number of investigators showed that a satisfactory antibody response could not be obtained with a single subcutaneous dose of 200 CCA units of vaccine. The 400 CCA units dose was distinctly superior. However, two injections of 200 CCA units of vaccine given 2 months apart produced a response better than a single injection of 400 CCA units.58 Subcutaneous injection of 20 or 40 CCA units in two doses, 2 weeks apart produced an antibody response similar to that produced by a single injection of 200 CCA units.59 Reasonably satisfactory results could be obtained by two intracutaneous or subcutaneous injections of 20 CCA units given 1 week apart.60 When 100 and 200 units were given subcutaneously, antibody response was clearly superior.
The Commission was able to obtain limited amounts of vaccine containing 200 or 400 CCA in September and provide enough for studies at Lowry Air Force Base, Fort Dix, Great Lakes, and Fort Ord. The last three based their data on hospital admissions; at Lowry Air Force Base diagnosis was
confirmed by serodiagnosis; with vaccine containing 200 CCA units, the VE was 60%; with vaccine containing 400 CCA units, the VE was 72%. Much helpful information was obtained about vaccines containing A strains. The protection was better with larger doses of virus but was less than that found in previous outbreaks.61
It was clear that a single dose of vaccine did not produce a satisfactory antibody response in persons who had no prior experience with that virus. Persons who had previously been exposed by infection or vaccination had a higher response when given vaccine after 3 months.
The Commission was confronted by a decision of the Army to discontinue annual influenza vaccination. The decision was administrative, based on the fact that during the last 5 years, influenza had been a mild illness of low incidence. The Commission pointed out that outbreaks had occurred in unvaccinated forces and intense outbreaks had been observed in civilian and military populations where vaccination was not carried out. It was pointed out that periods of major outbreaks had been preceded by a period of low incidence.
The decision not to use influenza vaccines apparently has been made on administrative grounds; from the scientific standpoint it is considered by the Commission to be untimely and unjustified. It is the belief, therefore, that vaccination against influenza should be continued on an annual basis throughout the Armed Forces.62
The second topic was a reappraisal of the direction of the Commission's activities. Each contractor had been requested to submit his views in writing to the Director prior to the meeting. The consensus was that the Commission should continue the studies on acute respiratory diseases. It seemed wise to reduce the size of these studies but to expand their scope so that more clinical, virologic, and serologic information could be obtained.
The outlook for efficacy of Asian virus vaccines in future epidemics was perceived to be much more promising because of the demonstration that a high level of antibody followed vaccination in persons previously exposed by infection or vaccination, at intervals of 6 weeks or 3 months.58 The two dose program of vaccination adopted by the military for 1958 and 1959 was expected to be highly effective if Asian influenza reappeared.
Asian virus strains were isolated from 24 fatal cases by 7 members or associate members of the Commission. The findings reemphasized the importance of Staphylococci in promoting a fatal outcome. However, in 12 of the fatal cases identified, no significant bacterial pathogen was found. Pregnancy or preexisting heart disease were conditions that predisposed to a fatal outcome.
Drs. Davenport and Hennessy compared Asian antibody levels in persons in different age groups in Ann Arbor. Their findings confirmed observations by Dr. Mulder that antibodies to Asian strains were present in sera of persons over 60 years of age; this suggested that a similar virus was present around the time of the pandemic of 1889 and 1890. These results suggested that a recycling of viruses was occurring.63
Adenovirus vaccine continued to give conflicting results, sometimes very favorable, sometimes disappointing. Dr. Loosli at San Diego, in laboratory-confirmed cases, reported protection against type 4 was about 72%.64
Dr. J. O. Culver at Fort Ord reported 93% effectiveness against type 4 adenovirus.65 Type 4 was a relatively poor antigen with great variability in the quality of the vaccine.
In all instances, the reduction of specific adenovirus rates was considerably greater than the overall reduction in the respiratory disease rates. It was estimated that a large percent of patients experienced illnesses other than those caused by adenoviruses. For that reason, the possibility of an adjuvant vaccine containing not only types 4 and 7 adenovirus, but also the JH agent, hemadsorption viruses (parainfluenza), and other uncharacteristic agents should be present and evaluated. The Commission proposed to develop studies of this nature.
Influenza Prevalence in 1959 and 1960
In 1959 and 1960, Asian influenza again appeared on a large scale. The incidence was high, and the excess deaths attributed to influenza and pneumonia exceeded the number observed at the peak of the fall outbreak of 1957. Curiously, little attention was paid to this by the public and press. The virus, which had been present since 1957, appeared four times in 4 years with no evidence of antigenic drift, which was unique in the history of influenza A infection. Despite a number of outbreaks with high attack rates in civilians, military personnel vaccinated in accordance with recommendations made by the Commission on Influenza were not significantly involved in the sharp outbreaks that civilians experienced in the surrounding communities.
A number of controlled studies during this outbreak demonstrated the effects of combined vaccine for both influenza and adenovirus infections. At Lowry Air Force Base, Dr. Meiklejohn tested the efficacy of a multivirus vaccine in emulsified mineral oil. The vaccine contained 350 CCA units of influenza viruses composed of the following: A/Jap/305/57 (H2N2), 100 units; A-prime (HIN1), 50 units; PR/ 8, 50 units; Swine, 50 units ; B-Lee /40, 50 units; and B-Great Lakes/54, 50 units. In addition, one-half the standard amounts of types 4 and 7 adenovirus were included. The crude reduction of illness in
this outbreak was 4:1. Adenovirus, type 7, and influenza infections occurred at the same time and this outbreak was fairly extensive. The serologic data indicated that protective efficacy against influenza A was approximately 94%, and against adenovirus type 7, was approximately 90%.66
Dr. Rose, working at Fort Dix, used a multivirus aqueous vaccine that contained, in addition to the types 4 and 7 adenovirus,1,000 CCA of aqueous influenza vaccine divided as follows: 400 CCA units of Asian, 100 units of A-prime, 100 CCA units of PR/8,100 units of Swine, 200 units of B-Great Lakes, and 100 units of B-Lee. This vaccine showed protective efficacy of 83% when compared with the standard Army influenza vaccine and demonstrated the practicality of combining influenza and adenoviruses in an aqueous vaccine or an emulsified mineral oil vaccine.67
Dr. Hennessy reported a protection ratio (VE 38%) in children aged 5 through 12 years of 1.6 to 1 against influenza B. The aqueous vaccine used contained four influenza virus strains, in addition to amounts of JH, 2060, HA1 and 2, CA, CCA , and adenovirus types 1, 2, 3, 4, 5, and 7. No significant reactions were noted. A difference in attack rate was found only during an outbreak of influenza B. This difference was small due to lack of adequate antibody response to the influenza B virus strains.67
Dr. Bryon Berlin continued his investigation of adjuvant vaccines. He was unable to find any animal or vegetable oil that was as effective as mineral oi1.60
Dr. Quilligan noted a protection ratio of approximately 3.7:1 (VE 73%) in children with mental handicaps who had received a monovalent vaccine in 1957 and again in January and May of 1958 and also in 1959. He made the interesting observation that febrile reactions declined with each vaccination.68
THE COMMISSION-1962 TO 1967
During the remainder of the A H2N2 decade, the Asian virus did not create any serious problems in the Armed Services. All personnel were vaccinated each year, and it was not possible to obtain any results from field trials. The alert systems showed that both influenzas A and B were present. In many communities the occurrence of outbreaks of influenza infection affected 20% of the community but did not appear to cause any problems in the Armed Services even though the virus had been repeatedly introduced at the bases.
The Commission maintained its operations much as before, with members and associates of the Commission involved in the following field studies: (a) Dr. Rose at Fort Dix in collaboration with the Army group at WRAIR; (b) Dr. Chanock at Camp Lejeune and Parris Island with the naval base there; (c) Drs. Francis and Davenport at Great Lakes Naval Station cooperating with NAMRU 4; (d) Dr. William Mogabgab at Keesler Air Force Base in Louisiana; (e) Dr. Meiklejohn at Lowry Air Force Base in Denver; and (f) Dr. Loosli with naval and marine units in San Diego.
Adenovirus infections appeared to increase in importance. They had become an even more serious problem than influenza in terms of morbidity from viral respiratory disease.
A number of field studies during this period showed clearly that both inactivated and live oral vaccines were effective in protecting against adenovirus illness and by the end of the period it was clear that the illness caused by adenoviruses types 4 and 7 could be essentially eliminated as a cause of morbidity. With influenza under control and adenoviruses virtually eliminated, research activities turned toward the probable causes of other febrile respiratory illnesses in the military. A number of Commission members began to study the remaining 50% of acute upper respiratory tract infections that occurred in the military and for which the etiology was unknown. The role of other viruses such as parainfluenza viruses, enteroviruses, coronaviruses, rhinoviruses, respiratory synsitial virus, and mycoplasma pneumonia were studied to determine their roles as causes of illness in the Armed Forces. Drs. Lennette and Mogabgab obtained valuable information on the role of rhinoviruses as causes of illness in Army and Air Force personnel.69, 70
An epidemic of influenza B in 1962 caused considerable mortality in the civilian community but did not cause significant illness in the military. The vaccine at that time contained two influenza B strains, B-Lee/40 and B-Great Lakes/54, which had been added to the vaccine when it appeared that there had been significant antigenic drift away from the B-Lee virus. The Commission considered changing the vaccine composition again but decided it was unnecessary because Captain Lloyd Miller at Great Lakes had observed good protection with a similar vaccine in 1959 against a virus very similar to the one that appeared in 1962.71
In the search for vaccine that would provide long lasting immunity and a response adequate to protect against virus strains that had drifted away from the vaccine virus, attention was focused on Dr. Salk's adjuvant vaccine. This preparation was shown by a number of investigators to provide a level of protection that would last for several years. Objections to the use of this adjuvant vaccine in the military were as follows: (a) Cysts developed in a certain proportion of recipients 2 to 3 months after administration and some had to be drained surgically. (b) There was concern about oncogenecity because of the presence in the adjuvant of components that had been shown to cause tumors in tumor-prone animals. (c) There was concern over the risk of hypersensitivity and hyperimmunization. To investigate these risks, a contract was formulated with Dr. Gilbert Beebe to follow, through the Veterans Administration (VA) system, records of 44,459 military personnel who had been vaccinated at Fort Dix in 1962 under the direction of Dr. Salk.72 Of these, 18,251 had received adjuvant vaccine, 4,317 had received aqueous vaccine, and 21,891 had received formalinized saline.
Dr. Salk believed that the cysts occurred for two reasons: (1) in England, where a large number of individuals had developed cysts, he thought that the lot of vaccine used contained a particularly "toxic" batch of Arlacel, and (2) the injection of the adjuvant vaccine into the subcutaneous tissue rather than intramuscularly accounted for most of the remaining cysts. It was noted that the amount of mineral oil injected into each person was very small, 0.25 mL. Advantages of adjuvant preparations were considered to be more important than the risks. It was recommended that the vaccine be used as a combined influenza adenovirus preparation.71
The question of hypersensitivity and hyperimmunization had been raised at Fort Detrick, Frederick, Maryland, and Dr. Leigh Cluff investigated this possibility. Results were essentially negative.73 Major Haycraft in Omaha, Nebraska, in collaboration with the Ann Arbor group, looked into this question in Strategic Air Command crews, who were regarded as the most intensely immunized group in the Armed Services. Major Haycraft carried out meticulous studies and found no difference when compared to a control group.
The threat of epidemic influenza during this period was very slight. All persons in the Armed Forces were vaccinated. The question was raised whether there was sufficient gain for the military to give multiple annual doses of the influenza vaccine. A collaborative study to look into this question was arranged between Dr. Davenport and Colonel Ralph C. Singer, Chief of Preventive Medicine of the Army. They found that most permanent party members, even though they had received a number of annual revaccinations, lacked antibody to the newly arrived strain that appeared in the following year. It had been noted earlier that these persons almost always responded very well to the booster. An excellent response was almost always observed in recruits who received vaccine for the first time. It was concluded that primary vaccination of recruits was essential and that annual revaccination of seasoned troops might well provide considerable benefit.74
During this period, a number of observations was made on the tolerance of various population groups to amantadine. The drug was effective against influenza A, but not influenza B. Captain Peckinpaugh found that doses of either 200 mg Amantadine or 300 mg of rimantadine did not produce significant toxicity in training personnel.74 In Ann Arbor, Drs. Quilligan and J. F. Finklea found the
toxicity of amantadine to be quite low in children.75 Dr. Hassan Maassab found that rimantadine was slightly more potent than amantadine.76
Dr. Edwin D. Kilbourne was interested in determining whether interferon induction could be of use in control of the viral infections. In 1967, Dr. Francis was presented the Outstanding Civilian Service Award by Major General James T. McGibony on behalf of Surgeon General Leonard D. Heaton. A partial record of General McGibony's remarks is as follows:
No words nor awards can recompense Dr. Francis for the endless sacrifices and contributions he has made. His own words which, with his permission I quote, best describe his own, as well as my evaluation of his service. In August he wrote to General Heaton the following: "I can assure you that (my services to the Army through the Armed Forces Epidemiological Board) have been the most rewarding activity in which I have ever been engaged. It has, in fact, embodied a dedication to the concept that preventive medicine is the key to the development and preservation of vigorous military forces. It has been my pleasure, my pride, and my honor to have served in these activities."
At the November meeting in 1968, the Commission noted the death of Dr. Bell (epidemiologist for the U.S. Public Health Service), who had been with the Commission since its early days. The minute adopted by the Commission was as follows:
Toward its mission Dr. Joseph A. Bell brought the experience of a career devoted to the prevention and control of acute respiratory disease-he constantly sought new epidemiological approaches to the study of preventive measures. His lively spirit as well as his broad insight were valuable contributions to the Commission's deliberations. He and his constructive judgment will be sorely missed.
THE COMMISSION-1968 TO 1972
The last 5 years of the Commission proved to be an interesting and exciting period. Influenza A virus had again experienced an antigenic shift with the appearance of Hong Kong-type viruses. The story of how the virus was discovered and how things proceeded from that point is of considerable interest and for that reason is presented in some detail.
In late July 1968, Dr. Francis was traveling from Europe to Tokyo. He stopped for one night in Hong Kong and, reading the local paper, learned of a sharp outbreak of influenza. Dr. E. S. Chang at the WHO laboratory in Hong Kong had isolated a virus in rhesus monkey kidney tissue culture that had been identified as influenza A at the laboratory in England that was the European strain typing center. Dr. Francis proceeded to Tokyo where he conferred with the senior personnel of the 406th Army Laboratory and the South East Asia Treaty Organization laboratory (Bangkok), which happened to be in Tokyo at the time.
He also contacted Dr. Hideo Fukumi, who had conducted research at the Ann Arbor laboratories in the School of Public Health in Michigan. He notified Dr. Davenport, Director of the Commission, that there was an influenza epidemic in Hong Kong. Dr. Davenport immediately contacted Colonel Singer. They discussed the situation and agreed on a program of activities. It seemed likely that the presence of qualified personnel at the 406th laboratory in Tokyo made it unnecessary for Commission personnel to collect specimens for viral isolation. On 20 July and 8 August, samples were received from Hong Kong.
Meanwhile, the Commission and Colonel Singer had met and agreed that monovalent vaccine (A/H3N2) should be given to the troops as soon as possible. The strains that had been received from
the Armed Forces were all isolated in monkey kidneys and were considered unsuitable for vaccine production. The first virus strain, A/Aichi/8/68 (H3N2), isolated in eggs, arrived in the Ann Arbor laboratory on 29 August 1968 from Dr. Fukumi, who had collected specimens from the crew of an Israeli ship that had recently arrived from Hong Kong. The first strains isolated in eggs in a military laboratory in Tokyo arrived in Ann Arbor in September. The A/Aichi/8/68 strain was considered suitable for vaccine production and was forwarded promptly to the Division of Biologic Standards for distribution to manufacturers. As a result of the delay in isolation of virus strains suitable for vaccine production, most Hong Kong vaccine reached the Armed Services after the epidemic had passed its peak.
Despite concern that the new virus might cause a pandemic similar to that observed 10 years before, no serious problems were encountered at the military bases. Field studies had been set up at five bases. In only two of these was there a significant incidence of influenza (Lowry Air Force Base and Keesler Air Force, Base). Drs. Theodore Eickhoff and Meiklejohn observed that adjuvant vaccines containing A/Taiwan/64 appeared to have roughly 50% effectiveness against Hong Kong influenza.77 Dr. Mogabgab reported that the aqueous Hong Kong vaccine provided a higher level of protection.78 The attack rate was very low in both these studies, but nonetheless the trend was there. The rates in civilians were much higher than in the Armed Services. At Lowry Air Force Base, a high rate of serologic conversion was observed in individuals who did not report to sick call, and it was estimated that 72% of the personnel had been infected by the Hong Kong virus during the season. The sparing of the military personnel may have been due, in part, to the fact that neuraminidase was the same in the H3N2 virus as in the H2N2 viruses that had been prevalent during the receding decade. This was in line with Dr. Kilbourne's observations about neuraminidase antibody.79
The standardization of vaccines was greatly improved during this period by Dr. Nicola Tauraso of the Division of Biologic Standards of the NIH. The procedures for vaccine manufacture were much improved and the highly purified vaccines contained pure virus particles. Reactions became far less common than in the past.
The meeting of the Commission in November 1969 was saddened by the report of Dr. Francis' death. The Commission expressed its deep sense of obligation and grief by adopting the following minute:
The members and associate members of the Commission on Influenza, Armed Forces Epidemiological Board, express their sorrow and deep sense of personal loss on the death of Dr. Thomas Francis, Jr., who was instrumental in organizing the Commission in 1941, served as its Director until 1955, and remained a member until 1 October 1969. Inspired by his leadership and guided by the brilliant example of his own scientific contributions, the Commission led the way in work that laid the foundation of modern research in influenza. In all of this work the Commission was encouraged and fortified by Dr. Francis' unswerving adherence to the principle that the continual acquisition of new information by basic scientific research is essential to any progressive program of development that is intended to solve practical problems.
The retirement of Dr. Francis as Director of the Commission in no way diminished his interest in its affairs. To the very end of his life he continued to give it the benefits of his remarkable wisdom, imaginative foresight, and unerring good judgment. All of the persons who had the privilege of association with him in the activities of the Commission are thankful for his friendship and stimulating presence, and they are mindful of the legacy of challenge he has bequeathed them. Dr. Francis had served as Director of the Commission from its founding in 1940 until 1955. He was replaced at that time by Dr. Davenport, who served until 1971.
A number of research activities of the Commission were continued during this period. Dr. Kilbourne showed that by a recombination procedure, a Hong Kong virus could be made with hemagglutinin
and neuraminidase with the growth characteristics of A/PR/8/34. This procedure was expected to facilitate the rapid production of vaccine.80
Dr. Hassan Maassab continued his work on cold adaptation81 and showed that in humans the live cold-adapted virus did not produce illness but did stimulate the production of antibody. He also compared the relative isolation rate of influenza virus in eggs and chick kidney cultures.
Dr. Rose, in collaboration with Dr. Councilman Morgan, reported on electron microscopic studies of the steps by which influenza virus enters cells and replicates. The sequence of events differed from that observed with adenovirus or parainfluenza viruses.82
Dr. Richard Winzler, continuing his studies on virus enzymes, showed that neuraminidase of influenza viruses slowly cleaved sialic acid.83 Dr. Herbert H. Blough reported his studies of the lipid incorporation into the viral membrane.84
Dr. Meiklejohn tested a small number of civilian volunteers with a second live Russian (H2N2) virus vaccine. As in a previous study, this type of vaccine produced antibody only in persons whose previous serum was devoid of antibody.85 Dr. Julius Younger reported results of the studies on the adjuvant properties of hexadecylamine.69 He made the interesting observation that use of this adjuvant caused response in some species but not in others. Unfortunately, humans turned out to be one of the species with no adjuvant response.
During the 1960s, it became clear that adenoviruses were, the major cause of morbidity in the recruit population of the three military services. Many studies had shown that most illness were due to either type 4 or type 7 adenovirus, with an occasional case infected with type 3. Inactivated vaccine against each type had provided a high percentage of efficacy in some studies, whereas others had shown relatively poor protection.
Adenovirus infections were a primary interest of the Commission on Acute Respiratory Diseases. Members of the Commission on Influenza became involved in adenovirus research because the technical procedures for the study of influenza provided a unique opportunity to obtain specimens for diagnosis of each type of infection. Dr. Hilleman at WRAIR had been the first to demonstrate the effectiveness of inactivated vaccine at Fort Dix.86 Colonel Edward Buescher was also interested in testing a live oral adenovirus vaccine that was given by mouth in an enteric capsule.87 It had been shown to be highly effective against type 4 and type 7. Dr. Chanock first had the clever idea of administering wild live virus in an enteric capsule. He recognized that the virus that propagated for a long time in the gut, like poliomyelitis, might immunize well against the respiratory challenge. The virus was cultured in Wistar Institute human embryonic lung fibroblast 38 cells and was not attenuated.88
Early in 1970, a committee was formed consisting of four members of the CARD and Dr. Meiklejohn of the Commission on Influenza. (With the exception of Dr. Harry Ginsberg, the Chairman, all others were also associate members of the Commission on Influenza. These were Dr. Chanock, Dr. George Gee Jackson, and Colonel Buescher [see Appendix 3].)
This committee was expected to make recommendations regarding live adenovirus vaccines. The committee recommended to the AFEB that the Army contract for acquisition of live oral vaccine, type 4, for use in recruits during the 1970 and 1971 influenza season. Further study of live type 7 vaccine, which had been shown to be equally effective, was recommended. When both vaccines were given together simultaneously, the antibody response was equally good for each virus.
The committee also urged further evaluation of capsid or subunit vaccine. There was considerable concern, particularly by Dr. Ginsberg, Director of the Commission on Acute Respiratory Diseases, about the possible onconogenicity of type 7 adenovirus. Previously, it was known that some type 7 strains had hybridized with SV40, an oncogenic virus of simian origin.
The original tests were highly successful. Later lots of vaccine were less effective and it was found that the titer of the virus had to be maintained at a minimum level of 10-5 ID 50. The question of possible oncogenicity was a troublesome one. Dr. Ginsberg submitted a minority report stressing his
Joseph Bell, a widely recognized epidemiologist, graduated in medicine from the University of Colorado in 1929. He trained in medicine and received his degree in public health from The Johns Hopkins School of Hygiene and Public Health in 1948. He was commissioned Assistant Surgeon General of the U.S. Public Health Service and devoted his entire professional life as a public servant.
Among his many distinguished memberships was the American Public Health Association, the Commission on Influenza of the AFEB, the American Epidemiologic Society (President, 1952), and the Association of Military Surgeons of the United States. His many creative contributions included design of the initial plans for the epidemiologic study of polio myelitis vaccine, membership on the Subcommittee on Control of Communicable Diseases of the American Public Health Association, and the WHO Expert Advisory Panel on International Quarantine.
reluctance to administer live type 7 vaccine to large numbers of recruits.
The majority of the committee believed the very high incidence of upper respiratory tract infection in recruit populations justified the use of the type 4 and type 7 vaccine. Furthermore, it had been clearly shown that almost all recruits not already infected would contact both types of adenoviruses infections during the first year or two of their military service.
The committee also recommended that oral type 14 and 21 vaccines should be developed experimentally. In Europe, sporadic outbreaks in military units had been attributed to these two viruses. It was made clear that virus surveillance should be carried out whenever possible to determine vaccine effectiveness and to determine any ill effects that might be related to the vaccine.
THE END OF THE COMMISSION
From the earliest studies at Fort Dix in the 1940s, there had been uneasiness on the part of Dr. Salk and others because the Department of the Army failed to provide medical officers assigned specifically for work on influenza vaccine field trials. Considerable personnel turnover at a large recruit base such as Fort Dix made it very difficult for any visiting epidemiologist to monitor personnel in vaccinated and control groups in any vaccine trial. Despite repeated requests by the Commission Director, the Army authorities often failed to provide personnel targeted for this type of activity. This experience appeared to differ from other AFEB Commission programs and could have represented a unique local difference. During the 1960s, disagreements continued to occur between Commission members and Army personnel. Frequently, these clashes were over the site of the annual meeting. Department of the Army authorities preferred to hold the meeting at WRAIR because of the convenience for related personnel; this also permitted broader attendance by interested military persons. Members of the Commission on Influenza preferred to hold the meeting at Ann Arbor. Undoubtedly, military travel restrictions and financial constraints influenced this attitude. This issue was compromised by holding two annual meetings: One scientific meeting at Ann Arbor for 3 days and a 1-day meeting at WRAIR, where administrative and pressing scientific problems were discussed. The latter meeting was small and was attended only by members of the Commission and involved military officers.
Dr. Davenport made a consistent effort to bring representatives of the three armed services and civilian groups such as the CDC and the NIH to the annual meetings. All persons holding contracts were invited to attend. Occasionally, directors of the other commissions attended meetings for presentation of interesting data (see Appendix 3)
Further disagreement developed in connection with the Commission's recommendation that the Department of the Army use vaccine prepared with adjuvant. This recommendation was never implemented. The Bureau of Biologics of the NIH did not approve adjuvant vaccine on the grounds that it was potentially oncongenic and would violate the Delaney Amendment. This amendment specified that no material should be injected into humans that was "oncogenic in any animal." "Oncogenicity" was based on injection of relatively large amounts of mineral oil into certain tumor-prone animals. Most Commission members believed that the risk of injecting vaccine that contained very small amounts of mineral oil into humans would be outweighed by elimination of the need for annual immunization against influenza. Also, it was concluded that better protection might be obtained against influenza, adenovirus, and other potential antigens that were to be added to the vaccine. Furthermore, Commission members were favorably influenced by the data collected by Dr. Beebe that showed no harmful effects among 18,000 persons who had received adjuvant vaccine 10 years previously. These data were thought to carry far more weight than the experimental data in animals provided by the Bureau of Biologics of the NIH. Nonetheless, the Army, reinforced by its legal division, accepted the position of the Bureau of Biologics.
The legal unit stressed that placebo studies involving Army volunteers could no longer be employed. Once a vaccine had been accepted for general use, it was held to be unethical to withhold it from any person. The irony of this position was not lost on a number of Commission members. They recalled the reluctance of some medical personnel in higher ranks to take vaccine on the grounds that little protection was provided or there were severe reactions. In addition, legal authorities added fuel to the fire by commenting that the Commission had violated several regulations relating to continued appointments and potential incidents of conflict of interest.
Without question, Army medical scientists and Commission members had drifted apart. Cooperative, favorable working relationships were maintained between the Commission and U.S. Navy and Air Force personnel. However, the Navy Department had begun looking to the National Research Council for technical advice on infectious diseases rather than to the Commission.
The nature of the differences between the regular Army personnel and the Commission remained troublesome. Dr. MacLeod, President of the AFEB in 1966, addressed these differences on the occasion of the 25th anniversary of the formation of the AFEB. His provocative comments included the following:
The military medical services have always had a difficult struggle to finance and man what they know has to be done to cope with present exigencies and future probabilities. They have known from the time of General Sternberg that they must be strong internally and this is very difficult to achieve when one considers that scientific contributions are not valued as highly in the military services as they should be in this scientific world we live in. Whoever heard of a First Lieutenant being made a full Colonel because he made a scientific discovery!
I am not giving lip service to the need to have high biomedical research competence in the military service. To the contrary, I believe it is absolutely essential that this be so and have consistently worked for it. Without it, the military simply could not take advantage of the scientific advances taking place throughout the scientific world.
At the same time, and based on considerable experience, I know that the day will never come when the military services can be scientifically self-sufficient in medicine any more than NIH in Bethesda can be for civil medicine.
The Armed Forces, therefore, must perfect even this extraordinary mechanism, the AFEB, to add new dimensions to their research toward the control of disease that they themselves through their intramural operations cannot hope to achieve alone.
So today I would like to reaffirm, and hopefully see enlarged, this partnership between the Armed Forces and civilian investigators that has been the envy of agencies throughout the government and I would like to see it explore new means of making this partnership more effective. Let us not be complacent in the face of events which drive us into traditional operating modes.
Despite Dr. MacLeod's urging for better relationships between the two groups, The Surgeon General of the Army appointed a Management Committee in 1971 to review activities of the AFEB. All government civilian agencies were subject to review at this time. This Committee was made up of the following members: Elliott J. William (Chairman), Department of the Army, Civilian Directorate of Plans, Supply and Operation, Office of The Surgeon General, Department of the Army; Phillip E. Winter, M.D., LTC, MC, USA, Directorate of Health and Environment, Office of The Surgeon General, Department of the Army; and Lieutenant Colonel France F. Jordan, MSC, U.S. Army Medical Research and Development Command.
The Committee was instructed to investigate a number of issues, including tenure of appointments and possible conflict of interests. After considering a number of possible alternatives, the Committee recommended that the AFEB continue as such with broader emphasis on chronic diseases. It further recommended that the Commissions be abolished to avoid any possible conflict or interest. The needs of the Army could be met because of the availability of trained medical officers, the emergence of an
"in-house military medical research and development community, and the growing effectiveness of the prevention of disease have materially lessened the requirement for AFEB assistance in both field investigations and the organization of contract research."90
A number of Commission members were hurt by the tone of this report. Only one member of the Commission on Influenza was consulted by the Management Committee. All members, during and after World War II, felt that they had fulfilled a national obligation and at the same time had given generously of their time without remuneration. Many members had directed their research efforts entirely in the direction of the scientific needs of the Armed Forces. Their only compensation was a fee of $50 per day during the time of the annual meetings of the Commission. It was fully acknowledged that the Army medical personnel at WRAIR had developed a considerable degree of competence. Many of these persons at WRAIR no longer sought advice from the Commission on Influenza, but had established relations with scientists at the NIH and CDC who they felt would provide guidance. Commission members surmised that WRAIR investigators would not be able to maintain adequate scientific competence, particularly in view of the fact that the physicians' draft would end. It was contemplated that with cessation of the Berry plan and the physicians' draft, the Army would have difficulty recruiting and retaining highly qualified personnel. With considerable regret, it became obvious that a close and effective relationship that had functioned effectively for more than 25 years and had greatly advanced the knowledge of influenza and other respiratory diseases would cease.
Dr. Davenport resigned as Director of the Commission on Influenza in 1971. He was succeeded by Dr. Meiklejohn who served as Director for the final 2 years of the Commission. The Commission ceased to exist on 1 January 1973.
When the Commission on Influenza was formed, very little was known about influenza or the viruses that caused it. At the time of its formation, the Commission established a comprehensive series of questions. The goals were fairly straightforward and the questions raised had almost been answered by the time World War II ended. The Commission showed that
. inactivated virus vaccine could protect against both influenzas A and B,
. immune serum given via the respiratory route did not protect against challenge with aerosols of the virus,
. the attack rate of influenza varied inversely with the HI antibody titer,
. immunity following natural infections was relatively weak (the fact that immunity was considerably reduced as early as 4.5 months after infection with wild virus made it seem unlikely that live attenuated virus would provide adequate protection; it was also conceived that the reversion of virus to a virulent type during laboratory experimentation with attenuated strains might lead to new outbreaks),
. influenza varied in great severity from the classic influenza in 1918 to an almost subclinical type of illness observed recently with influenza B,
. influenza virus was extremely unpredictable, which made it essential to conduct studies over a number of years to develop an immunity that would be long lasting.
During the years following World War II, much was learned about the virus in all respects. Antigenic shift, when new surface antigens appeared, occurred infrequently. However, repeated observations revealed that vaccine would provide a high level of protection and that it was worthwhile to vaccinate all military personnel annually. There continued to be questions about which virus strain
After graduation in medicine at Tulane, Harry Ginsberg trained in medicine and pathology for three years on the Harvard Service at the Boston City Hospital. Here he established friendships with John Dingle and Bill Jordan. During World War II he was Chief of Medicine at the U.S. Army Hospital, Ft. Bragg, North Carolina, where he showed that adenoviruses, type 4, was a cause of acute respiratory infections. At Ft. Bragg he was again associated with Dr. Dingle who directed the Commission on Acute Respiratory Diseases.
Three productive years were then spent with Frank Horsfall, at the Rockefeller Institute with work on influenza and viral pneumonia. He elucidated the genetics of adenovirus replication and virulence, particularly, type 5. He then joined Bill Jordan in John Dingle's outstanding department of Medicine at Case Western Reserve University. Harry then served with distinction at the University of Pennsylvania and Columbia University College of Physicians and Surgeons as chairman of microbiology. Even today, he arranges annual seminars on infectious disease problems and new vaccines and serves as a visiting scientist with Dr. Chanock at NIH. He rendered wise advice as a member of the Commission on Influenza of the AFEB.
After graduating in medicine from McGill University in 1937, Dr. Gordon Meiklejohn served his internship and residency in medicine at the Rockefeller Foundation. From 1944 to 1946, he served as a lieutenant in the U.S. Navy. He joined the faculty of the University of California, where he was appointed Professor of Medicine in 1951. From 1951 to 1975, Gordon served as the Distinguished Professor of Medicine and Chairman of the Department of Medicine at the University of Colorado in Denver.
Gordon is one of the most longstanding and devoted contributors to AFEB activities. He served as a member of the Commission on Influenza from 1948 to 1973, and directed that Commission from 1971 to 1973. He has been a pillar of support in conducting the year-to-year surveillance studies on the incidence of and the antigenic changes related to influenza. These continuing serologic observations, many of which are conducted at Lackland Air Force Base and other key laboratories, are closely correlated with those of the Centers for Disease Control in Atlanta, the World Health Organization, and the AFEB. These painstaking observations are of great importance in helping select the particular influenza viruses that are incorporated in new vaccines from year to year.
13 and 14 November 1972 Walter Reed Army Medical Institute of Research
Seated, left to right: Drs. Edwin D. Kilbourne, Frederick M. Davenport, Gordon N. Meiklejohn (Commission Director), Edwin H. Lennette, and Julius S. Younger.
Standing, left to right: Drs. Herbert A. Blough, Calderon Howe, Robert M. Chanock, Jerome L. Schulman, Purnell W. Choppin, and Albert V. Hennessy.
should be incorporated in the vaccine. Some favored a monovalent vaccine prepared from the most recently isolated strain. Others preferred a polyvalent vaccine containing, in addition to the newly isolated virus, representative strains from the earlier years. It was shown in 1957, when the Asian (H2N2) virus appeared, that an antibody was present in the sera of individuals in older age groups. This finding suggested that a similar virus had been present as far back as 1890. This led to the development of the "doctrine of original antigenic sin" proposed by the Ann Arbor group.91
Much interest focused on Dr. Salk's mineral oil Arlacel adjuvant that made it possible to obtain very high antibody levels with very small amounts of antigen. Such antibody responses persisted for several years rather than for only 1 to 2 years against influenza A. The most effective protection was obtained with adjuvant vaccine in 1960, at a level of 94%. Adjuvant vaccines were also shown to have the advantage of being able to incorporate many different strains of influenza virus as well as other viruses with a resultant good response to each component in terms of protective antibody.
It became obvious that as influenza came under control, a number of other viral agents were responsible for many of the upper respiratory tract infections. Commission members made these observations at a number of military bases in different parts of the United States. Adenovirus, in particular, caused considerable morbidity in a number of recruit installations. Commission scientists conducted studies of adenovirus vaccines that showed that either injected inactivated or orally administered live vaccines were highly effective in preventing type 4 and type 7 illness. The work in this area was coordinated with activities of the Commission on Acute Respiratory Diseases, which had carried responsibility for that particular project. The Commission also played a role in elucidating the etiology of "viral pneumonia" in inductees and isolation of the Eaton agent, which was shown to be the cause of the common variety of "atypical pneumonia."
During the latter part of the Commission's tenure, influenza was under control with vaccination for all military personnel. New studies on characterization of influenza virus were undertaken. A number of basic scientists were recruited to work with the Commission.
Dr. Maassab continued his work on cold adaptation of both influenzas A and B. Dr. Kilbourne developed a method of recombining a new virus with an old strain. This finding made it possible to combine hemagglutinin and neuraminidase antigens in a new virus with the growth characteristics of an old virus (PR/8). With Dr. Jerome Schulman, Dr. Kilbourne developed a mouse model to study the transmission of influenza by the airborne route.92 They also acquired much information on the neuraminidases of different strains of influenza viruses.
When the Commission's activities ceased in 1973, its members felt a fully justified sense of pride and satisfaction with the realization that its major responsibilities had been met and that the Armed Forces had been provided the means to control influenza to a very considerable extent. In addition, Commission-oriented research had established an awareness of the important potential of influenza virus. It was obvious that more work was needed and new data developed before there could be full assurances of investigative control of this old scourge in the future. Specifically, certain questions remained regarding the nature of antigenic drift, and the origin of new viruses such as A/H2N2 and A/H3N2. Furthermore, it was patently obvious that many persons escaped influenza infection in spite of low levels of HI antibody. This fact alone made it clear that more data were needed to clarify the nature of immunity.
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SECTION 2-APPENDIX 1
EXPERIMENTAL CHALLENGE OF VACCINATED PERSONS
Influenza A(102 volunteers)
Comment: Definite evidence of protection at 2 weeks, less at 4.5 months after vaccination.
Influenza B (96 volunteers)
Incubation period = 12 to 24 hours
Comment: Definite evidence of protection against influenza B. In contrast to results with influenza A, no difference was observed in persons vaccinated either 4 weeks or 4.5 months previously.
SECTION 2-APPENDIX 2
INTRANASAL SERUM PROPHYLAXIS
Comment: No evidence of protection.
Comment: No evidence of protection.
SECTION 2-APPENDIX 3
ATTENDANCE AT 1968 ANNUAL MEETING OF COMMISSION ON INFLUENZA
Annual meeting of the Commission on Influenza held 17, 18, and 19 November 1968 in Ann Arbor, Michigan. Those attending were:
Dr. Frederick M. Davenport
Dr. Byron S. Berlin
Dr. Gilbert W. Beebe
Director of the Commission on Influenza: Dr. Frederick M. Davenport, M.D.
*Members of the Commission on Acute Respiratory Diseases (CARD)