The Great Influenza (62 page)

They had prepared and distributed a vaccine based largely upon their conviction.

But even Park and Williams had made compromises. Now, as the epidemic waned, they continued their investigations with great deliberateness. They had always been best at testing hypotheses, looking for flaws, improving upon and expanding others' more original work. Now, chiefly to learn more about the organism in the hope of perfecting a vaccine and serum (but also to test their own hypothesis that
B. influenzae
caused influenza) they started an extensive series of experiments. They isolated the bacillus from one hundred cases and succeeded in growing twenty pure cultures of it. They then injected these cultures into rabbits, waited long enough for the rabbits to develop an immune response, then drew the rabbits' blood, centrifuged out the solids, and followed the other steps to prepare serum. When the serum from each rabbit was added in test tubes to the bacteria used to infect that rabbit, the antibodies in the serum agglutinated the bacteria - the antibodies bound to the bacteria and formed visible clumps.

They had expected that result, but not their next ones. When they tested these different sera against other cultures of Pfeiffer's, agglutination occurred only four of twenty times. The serum did not bind to the Pfeiffer's in the other sixteen cultures. Nothing happened. They repeated the experiments and got the same results. All the bacterial cultures were definitely Pfeiffer's bacillus, definitely
B. influenzae
. There was no mistake in that. All twenty of their sera would bind to and agglutinate bacteria from the same culture used to infect that particular rabbit. But only four of the twenty different sera would bind to any bacteria from another culture of Pfeiffer's.

For a decade scientists had tried to make vaccine and antiserum for Pfeiffer's influenza bacillus. Flexner himself had tried soon after Lewis left the institute. No one had succeeded.

Park and Williams believed they now understood why. They thought Pfeiffer's resembled the pneumococcus. There were dozens of strains of pneumococci. Types I, II, and III were common enough that a vaccine and serum had been made that could protect somewhat against all three, though with truly good effect only against Types I and II. So-called Type IV wasn't a type at all: it was a grab-bag designation of 'other' pneumococci.

As they explored Pfeiffer's further, they became more and more convinced that
B. influenzae
similarly included dozens of strains, each different enough that an immune serum that worked against one would not work against the others. In fact, Williams found 'ten different strains in ten different cases.'

In early 1919, Park and Williams reversed their position. They stated, 'This evidence of multiple strains seems to be absolutely against the influenza bacillus being the cause of the pandemic. It appears to us impossible that we should miss the epidemic strain in so many cases while obtaining some other strain so abundantly. The influenza bacilli, like the streptococci and pneumococci, are in all probability merely very important secondary invaders.'

The influenza bacillus, they now said, did not cause influenza. Anna Williams wrote in her diary, 'More and more, evidence points to a filterable virus being the cause.'

* 

Many others were also beginning to think that a filterable virus caused the disease. William MacCallum at the Hopkins wrote, 'In Camp Lee we found practically no influenza bacilli' . At the Hopkins Hospital influenza bacilli was rarely found' . Since a great many different bacteria have been found producing pneumonia, often in complex mixtures, it would require very special evidence to prove that one of these is the universal cause of the primary disease. And since this particular organism is by no means always present it seems that the evidence is very weak. Indeed, it appears probable that some other form of living virus not recognizable by our microscopic methods of staining, and not to be isolated or cultivated by methods currently in use, must be the cause of the epidemic.'

But the subject remained controversial. No evidence pointed toward a filterable virus except negative evidence - the absence of proof of anything else. And the theory that a virus caused influenza had already been tested by excellent scientists. During the very first outbreak of the second wave in the United States, Rosenau had suspected a filterable virus. Indeed, he had suspected it at least since 1916. His instincts led him to conduct extensive and careful experiments with sixty-two human volunteers from the navy brig in Boston. He collected sputum and blood from living victims and emulsified lung tissue of the dead, diluted the samples in a saline solution, centrifuged them, drained off the fluid, and passed them through a porcelain filter, then tried various methods to communicate the disease to the volunteers. He used every imaginable method of injection, inhalation, dripping into nasal and throat passages, even into the eyes, using massive life-risking dosages. None of the volunteers got sick. One of the physicians conducting the experiments died.

In Germany a scientist had also tried, spraying the throats of volunteers with filtered nasal secretions, but none of the subjects got influenza. In Chicago a team of investigators failed to infect human volunteers with filtered secretions of influenza victims. Navy investigators in San Francisco failed.

Only one researcher in the world was reporting success in transmitting the disease with a filtrate: Charles Nicolle of the Pasteur Institute. But Nicolle's entire series of experiments involved fewer than a dozen people and monkeys. He tried four separate methods of transmitting the disease and claimed success for three of them. First he dripped filtrate into the nasal passages of monkeys and reported they got influenza. This was possible, although monkeys almost never get human influenza. He injected a filtrate into the mucosal membranes around the eyes of monkeys and reported they got influenza. This was theoretically possible, but even less likely. He also claimed to have given two human volunteers influenza by filtering the blood from an ill monkey and injecting the filtrate subcutaneously - under the men's skin. Both of the men may have gotten influenza. Neither of them could have gotten it by the method Nicolle claimed. Nicolle was brilliant. In 1928 he won the Nobel Prize. But these experiments were wrong.

So, lacking other candidates, many scientists remained convinced Pfeiffer's did cause the disease, including most of those at the Rockefeller Institute. So did Eugene Opie, Welch's first star pupil at the Hopkins, who had gone to Washington University in St. Louis to model it after the Hopkins, and had led the laboratory work of the army's pneumonia commission. In 1922 he and several other commission members published their results in a book called
Epidemic Respiratory Disease
. One coauthor was Thomas Rivers, who by then had already begun working on viruses; in 1926 he defined the difference between viruses and bacteria- creating the field of virology and becoming one of the world's leading virologists. But he spent his first five years after the war continuing to research Pfeiffer's, writing many papers on it even while beginning his viral researches. He recalled, 'We managed to get influenza bacilli out of every person that had an attack of influenza' . We found it and quickly jumped to the conclusion that the influenza bacillus was the cause of the pandemic.'

* 

What it came down to was that nearly all investigators believed their own work. If they had found the influenza bacillus in abundance, they believed it caused influenza. If they had not found it, they believed it did not cause influenza.

Only a very few saw beyond their own work and were willing to contradict themselves. Park and Williams were among these few. In doing so they demonstrated an extraordinary openness, an extraordinary willingness to look with a fresh eye at their own experimental results.

Park and Williams had convinced themselves (and many others) that the influenza bacillus did not cause influenza. Then they moved on. They stopped working on influenza, partly out of conviction, partly because the New York City municipal laboratory was losing the funding to do true research. And they were getting old now.

Through the 1920s, investigators continued to work on the problem. It was, as Burnet said, the single most important question in medical science for years.

In England, Alexander Fleming had, like Avery, concentrated on developing a medium in which the bacillus could flourish. In 1928 he left a petri dish uncovered with staphylococcus growing in it. Two days later he discovered a mold that inhibited the growth. He extracted from the mold the substance that stopped the bacteria and called it 'penicillin.' Fleming found that penicillin killed staphylococcus, hemolytic streptococcus, pneumococcus, gonococcus, diphtheria bacilli, and other bacteria, but it did no harm to the influenza bacillus. He did not try to develop penicillin into a medicine. To him the influenza bacillus was important enough that he used penicillin to help grow it by killing any contaminating bacteria in the culture. He used penicillin as he said, 'for the isolation of influenza bacilli.' This 'special selective cultural technique' allowed him to find 'B. influenzae in the gums, nasal space, and tonsils from practically every individual' he investigated.

(Fleming never did see penicillin as an antibiotic. A decade later Howard Florey and Ernst Chain, funded by the Rockefeller Foundation, did, and they developed Fleming's observation into the first wonder drug. It was so scarce and so powerful that in World War II, U.S. Army teams recovered it from the urine of men who had been treated with it, so it could be reused. In 1945, Florey, Chain, and Fleming shared the Nobel Prize.)

In 1929 at a major conference on influenza, Welch gave his personal assessment: 'Personally I do feel there is very little evidence that [
B. influenzae
] can be the cause. But when such leading investigators as Dr. Opie, for example, feel that the evidence is altogether in favor of Pfeiffer's, and take the further exasperating position that the failure of other bacteriologists to find it was due to error in technique, to lack of skill, one cannot say there is not room for further investigation' . The fact has always appealed to me that influenza is possibly an infection due to an unknown virus' with this extraordinary effect of reducing the resistance so that the body, at least the respiratory tract, becomes such that any organisms are able to invade and produce acute respiratory trouble and pneumonia.'

In 1931, Pfeiffer himself still argued that, of all organisms yet described, the pathogen he had called
Bacillus influenzae
and that informally bore his name had 'the best claim to serious consideration as the primary etiologic agent, and its only competition is an unidentified filterable virus.'

* 

Avery continued to work on the influenza bacillus for several years after the pandemic. As his protegé René Dubos said, 'His scientific problems were almost forced on him by his social environment.' By that he meant that the Rockefeller Institute influenced his choice of problems. If something mattered to Flexner and Cole, Avery worked on it.

And he made remarkable progress, proving that passage in animals did make the bacillus more lethal and, far more importantly, isolating the factors in blood that
B. influenzae
needed to grow, initially identifying them as 'X' and 'V.' It was extraordinary work, work that marked a milestone in understanding the nutritional needs and metabolism of all bacteria.

But as the likelihood of the influenza bacillus causing influenza began to fade, the pressure on him to work on it faded also. Although he had initially inclined toward the view that it caused influenza, he became one of the increasing number of scientists who believed
B. influenzae
had been misnamed. He had no inherent interest in the organism and had never abandoned his work on the pneumococcus. Far from it. And the epidemic had driven home more than ever the lethal nature of pneumonia. Pneumonia had done the killing. It remained the captain of the men of death. Pneumonia was the target. He returned to his work on the pneumococcus full-time. He would study it for the rest of his scientific life.

In fact, as first months and then years passed, Avery seemed to limit his entire world to the research he himself engaged in. He had always focused. Now his focus tightened. Even Dubos said, 'I was often surprised and at times almost shocked by the fact that his range of scientific information was not as broad as could have been assumed from his fame and from the variety and magnitude of his scientific achievement.' Another time Dubos observed, 'He made little effort to follow modern trends in science or other intellectual fields, but instead focused his attention on subjects directly related to the precise problem he had under study. In the lab he was limited to a rather narrow range of techniques, which he rarely changed and to which he added little.'

His interests increasingly narrowed to one interest, the one thing he was trying to comprehend: the pneumococcus. It was as if his mind became not only a filter but a funnel, a funnel that concentrated all the light and information in all the world on one point only. And at the bottom of this funnel he did not simply sit, sifting through data. He used its edges to dig deeper and deeper into the earth, tunneling so deep that the only light present was that which he carried with him. He could see nothing but what lay before him.

And, more and more, he began to narrow his focus even further, to a single aspect of the pneumococcus - to the polysaccharide capsule, the M&M-like sugar shell surrounding it. The immune system had great difficulty attacking pneumococci surrounded by capsules. Encapsulated pneumococci grew rapidly and unimpeded in the lungs; they killed. Pneumococci without capsules were not virulent. The immune system easily destroyed them.

At the lunch tables at the institute, sitting in the comfortable chairs, pulling apart baguettes of French bread, drinking an endless supply of coffee, scientists learned from each other. The tables were of eight, but usually one senior person would dominate a discussion. Avery spoke little, even as he grew in stature and seniority; yet he dominated in his own way, asking pointed questions about problems that confronted him, searching for any ideas that might help.