In recent months, Americans looking for eggs have faced empty shelves in their grocery stores. The escalating threat of avian flu has forced farmers to kill millions of chickens to prevent its spread.
Nearly 70 years ago, Maurice Hilleman, an expert in influenza, also worried about finding eggs. Hilleman, however, needed eggs not for his breakfast, but to make the vaccines that were key to stopping a potential influenza pandemic.
Hilleman was born a year after the notorious 1918 influenza pandemic swept the world, killing 20 million to 100 million people. By 1957, when Hilleman began worrying about the egg supply, scientists had a significantly more sophisticated understanding of influenza than they had previously. This knowledge led them to fear that a pandemic similar to that of 1918 could easily erupt, killing millions again.
As a historian of medicine, I have always been fascinated by the key moments that halt an epidemic. Studying these moments provides some insight into how and why one outbreak may become a deadly pandemic, while another does not.
Anticipating a pandemic
Influenza is one of the most unpredictable of diseases. Each year, the virus mutates slightly in a process called antigenic drift. The greater the mutation, the less likely that your immune system will recognize and fight back against the disease.
Every now and then, the virus changes dramatically in a process called antigenic shift. When this occurs, people become even less immune, and the likelihood of disease spread dramatically increases. Hilleman knew that it was just a matter of time before the influenza virus shifted and caused a pandemic similar to the one in 1918. Exactly when that shift would occur was anyone’s guess.
In April 1957, Hilleman opened his newspaper and saw an article about “glassy-eyed” patients overwhelming clinics in Hong Kong.
The article was just eight sentences long. But Hilleman needed only the four words of the headline to become alarmed: “Hong Kong Battling Influenza.”
Within a month of learning about Hong Kong’s influenza epidemic, Hilleman had requested, obtained and tested a sample of the virus from colleagues in Asia. By May, Hilleman and his colleagues knew that Americans lacked immunity against this new version of the virus. A potential pandemic loomed.
The U.S. prioritized vaccinating military personnel over the public in 1957. Here, members of a West German Navy vessel hand over a jar of vaccine to the U.S. transport ship General Patch for 134 people sick with flu.
Henry Brueggemann/AP Photo
Getting to know influenza
During the 1920s and 1930s, the American government had poured millions of dollars into influenza research. By 1944, scientists not only understood that influenza was caused by a shape-shifting virus – something they had not known in 1918 – but they had also developed a vaccine.
Antigenic drift rendered this vaccine ineffective in the 1946 flu…
