Gina Kolata's telling of the story of the 1918 influenza pandemic reveals how modern medicine, basking in the success that the new germ theory of disease had brought, was utterly unprepared for, and therefore completely helpless in the face of, the pandemic that ravaged the world. This flu was unlike any flu encountered before: it was 25 times more lethal than ordinary influenzas, killing 2.5 percent of its victims, in contrast to the normally observed 0.1 percent mortality. Worldwide, possibly 50 million people died. That the pandemic was caused by a virus was discovered in the 1930's; yet scientists remained troubled by their lack of understanding of the virus, where it came from, and what made it so lethal. They realized the only way they would solve the mystery was to somehow obtain the actual 1918 influenza virus itself.
Enter Johan Hultin, in 1951 a 26-year-old Swedish postgraduate student studying in the United States. In 1936 scientists had learned how to grow influenza viruses in fertilized hen's eggs, and Hultin decided to attempt to retrieve the 1918 flu virus from victims who had been buried up north in permafrost and whose bodies were therefore well preserved. By growing it up scientists would be able to study it, perhaps learn what made it so deadly, and make a vaccine so that there would never be a repeat of 1918. He was able to obtain some specimens from a burial site in a tiny Alaskan village called Brevig, but he was unable to grow it. It seemed that, for the time being, he was at a dead end.
The 1976 swine flu episode in the United States demonstrated how the long shadow of 1918 could still influence the objectivity of scientists, how despite the huge gains made in virology in the intervening years, the lack of hard data about the Spanish Flu virus would allow fear to tip the balance in the question of a nation-wide vaccination program. Though in hindsight we know it turned into an expensive fiasco and a nightmare of litigation, Kolata is reserved in her criticism: "For even now, more than two decades later, it is not clear that the scientists had much choice in their decisions or that, if they had to do it over again, they would make radically different decisions." Indeed, the argument for vaccination was persuasive: first, there was evidence of a new flu strain with man-to-man transmission; second, always before when a new strain was found there was a subsequent pandemic.
Possibly, in retrospect, better judgment would have prevailed if an answer to a simple question would have been required of the scientific advisors: what information might make the group change its mind about the need to prepare to immunize the nation against swine flu? Would it be evidence that every swine flu case was mild? Or that no one but the Fort Dix soldiers (where the only fatality occurred) got the swine flu? Because in the end, the decision was made to vaccinate everyone for a disease that no one could prove to even exist. It was, then, the metaphor of 1918, the "vivid images rooted in folk history", rather than hard science, that drove the decision. So the lesson from 1976 was that if a new virus appears, you shouldn't jump the gun and assume a pandemic is happening.
More recently science has made headway in tackling some of the biggest questions remaining from 1918, including why the age group usually best able to resist serious infection, people aged 20 to 40, in this case suffered the highest rates of mortality (along with the very young and very old). One theory is that a viral strain similar to, but less lethal than, the 1918 strain, circulated the world in the late 1800's so that those above 40 years old would have had some immunity to the 1918 strain, but those below 40 would have been completed blindsided by the new virus. Another theory is that the virus killed by inducing something called a "cytokine storm" which is a potentially fatal over-reaction by the immune system. Those most susceptible to cytokine storm would be those with the most vigorous immune systems, namely adults between 20 and 40.
Johan Hultin's part in the story was by no means over in 1951. He went on to a successful career as a pathologist, but never forgot about his burning desire to be a part of solving the Spanish flu mystery. As the years passed he observed the development of molecular biology techniques, and with the advent of PCR, he knew that the time had come for a repeat visit to Brevig. After obtaining the cooperation of a molecular biologist, Dr. Jeffrey Taubenberger, in 1997 he returned to Brevig, a self-funded, solitary trip done in utter secrecy. He was successful in finding specimens from one more well-preserved body. In addition to this specimen, Taubenberger's team had located in a medical storage warehouse, lung specimens from two soldiers who had died from the 1918 flu. Using PCR, they were able initially to sequence the hemagglutinin gene from each of the three, and by 2005, the whole genome of the virus. We can now say that the Spanish Flu was caused by an avian strain of H1N1.
However, despite all the increases in knowledge since 1918, the scientific community is divided as to our capacity to handle a similar outbreak today. Some are confident that because of the surveillance we now have, combined with new antiviral drugs like Tamiflu, and the potential for vaccines, we will never have a repeat of 1918. But others are far less optimistic, suggesting that even a best-case scenario would have 20 million deaths worldwide, while a worst-case scenario would have a death toll exceeding that of 1918. As the 2009 "Swine Flu" pandemic continues on through the summer and the autumn flu season approaches, this admitted uncertainty gives little confidence to observers such as myself.
