How the U.S. Fought the 1957 Flu Pandemic

The story of the medical researcher whose quick action protected millions of Americans from a new contagion

Vial and packaging for the 1957 H2N2 vaccine
Vial and packaging for the 1957 H2N2 vaccine, at the National Museum of American History. Producing the inoculation required hundreds of thousands of fertilized chicken eggs per day. National Museum of American History

In April 1957, a new strain of a lethal respiratory virus emerged in East Asia, caught local health authorities by surprise and eventually killed masses of people worldwide. Today, in the age of Covid-19, that scenario sounds frighteningly familiar—with one key difference. Maurice Hilleman, an American microbiologist then running influenza monitoring efforts at the Walter Reed Army Institute of Research, saw the problem coming and prepared the United States ahead of time. “This is the pandemic,” he recalled saying. “It’s here.”

Hilleman arranged for the U.S. military to ship samples of the pathogen, believed to be a novel influenza virus, from Hong Kong to his lab in Washington, D.C. For five days and nights, his team tested it against blood from thousands of Americans. They found that this strain, H2N2, was unlike any flu that humans were known to have encountered. When it reached the United States, no one would be immune.

Hilleman moved quickly to alert the government, even predicting when the virus would hit U.S. shores: the first week of September, right when schools would reopen. In the years since the 1918 pandemic, health officials had lost sight of the deadly power of aggressive strains of influenza viruses, and the U.S. Public Health Service ignored Hilleman’s warnings. “I was declared crazy,” Hilleman told the pediatrician Paul Offit, who reports the conversation in his book Vaccinated. Still, having identified the new strain, Hilleman sent samples of the virus to the six biggest pharmaceutical companies, directing them to produce a vaccine for this new flu—and they did, partly out of respect for Hilleman himself. “He had that sort of clout” within the industry, says George Dehner, a historian.

The pandemic of 1957-58 ultimately caused 1.1 million deaths worldwide, and it follows the 1918 crisis as the second-most severe influenza outbreak in U.S. history. Some 20 million Americans were infected, and 116,000 died. Yet researchers estimate that a million more Americans would have died if not for the pharmaceutical companies that distributed 40 million doses of Hilleman’s vaccine that fall, inoculating about 30 million people. His swift and perceptive response to the virus led one expert to predict, according to the New York Times, that Americans could look forward “to the time when common virus diseases will be preventable and treatable and even curable.”

Hilleman went on to join Merck & Co., where he developed vaccines for more than 40 diseases, including measles, mumps and meningitis. But as these illnesses faded from public memory, so did Hilleman, who died in 2005 at age 85. Alexandra Lord, chair and curator of medicine and science at the National Museum of American History, says one irony of public health is that “the more successful experts are, the more people forget about the dangers.”

Listen to Sidedoor: A Smithsonian Podcast

The second season of Sidedoor aired this episode, "Killer Viruses and One Man's Mission to Stop Them" about Maurice Hilleman's work on vaccines.

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