The American Plague - Molly Caldwell Crosby [107]
Max Theiler’s work in Boston caught the attention of some scientists working with the Rockefeller Foundation—one of which was Dr. Wilbur Sawyer. The Rockefeller Foundation offered Theiler double his salary at Harvard to join their yellow fever lab. Theiler accepted and began work with Sawyer on a vaccine to inoculate the doctors who worked in labs—doctors who continued to die from their work with yellow fever. Theiler himself had contracted yellow fever in the lab in 1929, but recovered, developing immunity. Recently, three other doctors had also developed yellow fever in their work in the United States and in Lagos; one had died. A vaccine would finally give the scientists trying to conquer yellow fever a fighting chance.
Sawyer and Theiler developed a makeshift vaccine combining the infected mouse-brain tissue with blood from a human immune to yellow fever. Then, they took the amalgam of virus and antibodies and injected it into a man named Bruce Wilson. Wilson, who had earned fame as a public health field director fighting against malaria, had just returned from Brazil. He was checked into a screened room at the Rockefeller Institute, where he was injected with this new vaccine. His temperature and pulse were monitored constantly, and to pass the time, Wilson taught his night nurse how to play poker. Wilson never grew ill, and instead, developed immunity to yellow fever.
They now decided to turn their attention to developing a large-scale, safe vaccine. French studies using Theiler’s mouse strain had produced some negative reactions. Even Sawyer had seen the occasional case of fatal encephalitis during his test studies on monkeys. They decided to try an entirely new vaccine using milder strains of yellow fever taken directly from monkeys, forgetting the mice all together. An extensive laboratory was set up in which thousands of flasks, a factory line of glass tubes, housed the virus—part of the Asibi strain—and reproduced it in various forms. They experimented with mouse embryos, then chicken embryos. With time, they developed what became known as the 17-D vaccine, grown in a chicken embryo and named for the seventeenth series of experiments and the type of tissue used. The only complication wasn’t really a complication at all: The virus required a little human nonimmune blood, a serum, to survive. The doctors therefore added about 10 percent human blood to the vaccine. It was cheap and safe—it seemed simple enough. But man continually underestimates nature, and as a result, nature occasionally makes folly out of man’s triumphs.
Scientists had now been working on a vaccine for nearly ten years. Throughout the 1930s, as America fell into a deep depression, the doctors locked themselves away in labs and engaged in this viral fertility study. They nurtured the yellow fever virus, disciplined it, fed it blood and grew it in the surrogate confines of a chicken egg.
By 1941, it seemed clear that America would soon be at war, and as every war in the past had taught, disease could be far more devastating than the enemy. Dr. Wilbur Sawyer worked on a mass production of the vaccine to inoculate American soldiers as they left to fight. Theiler had some reservations about the new vaccine though. He wanted to try a serum-free vaccine, one that could be used without introducing human blood into the mix. Sawyer thought it was a good idea in theory, but added that there simply