On April 17, 1957, Maurice Hilleman realized a pandemic was on its way to the United States. That day, The New York Times reported on a large influenza outbreak in Hong Kong. One detail in particular caught the doctor’s eye: in the long waiting lines for clinics, the paper said “women carried glassy-eyed children tied to their backs.” He quickly got to work, putting out the word that there was a pandemic coming and pushing to develop a vaccine by the time school started again in the fall.
The first case of the pandemic had appeared in the Guizhou Province of southwestern China in February 1957. By the time Hilleman read about it in April, the Times reported that an estimated 250,000 Hong Kong residents—or 10 percent of the region’s population—were receiving treatment for it.
“We all missed it,” he later recalled for The Vaccine Makers Project. “The military missed it, and the World Health Organization missed it.”
The day after reading the story, he sent a cable to an Army Medical General Laboratory in Zama, Japan, asking the staff to investigate what was going on in Hong Kong. A medical officer identified a member of the U.S. Navy who’d become infected in Hong Kong, and sent the serviceman’s saliva back to Hilleman in the United States so he could study the virus.
The 1957 Virus Shifted
As the chief of respiratory diseases at the Walter Reed Army Institute of Research in Washington, D.C., Hilleman “had access to large numbers of serum obtained from people at various ages through previous years and decades,” says pediatrician Paul A. Offit, who serves as director of the Vaccine Education Center at the Children’s Hospital of Philadelphia and is the author of Vaccinated: One Man's Quest to Defeat the World's Deadliest Diseases.
In his work at Walter Reed, Hilleman had made the critical observation that the two key proteins in the flu virus—hemagglutinin and neuraminidase—undergo slight changes, or “drift,” between seasons (this insight helped him predict the need for yearly flu vaccinations).
By comparing the Navy serviceman’s virus against previous flu viruses, “what he found was that there was this dramatic shift,” Offit says. “Both those proteins were completely different from what they had been previously. They hadn’t just drifted, they’d shifted.” This new virus was a completely different strain of the flu.