The autopsy revealed that Lewis had been killed by “swine flu,” an influenza virus originating in pigs. By then several other soldiers had been hospitalized with symptoms. Government doctors became alarmed when they discovered that at least 500 soldiers on the base were infected without becoming ill.

It recalled 1918, when infected soldiers returning from the trenches of World War I triggered a contagion that spread quickly around the world, killing at least 20 million people. Fearing another plague, the nation’s health officials urged Ford to authorize a mass inoculation program aimed at reaching every man, woman and child. He did, to the tune of $135 million ($500 million in today’s money).

Mass vaccinations started in October, but within weeks reports started coming in of people developing Guillain-Barré syndrome, a paralyzing nerve disease, right after taking the shot. Within two months, 500 people were affected, and more than 30 died. Amid a rising uproar and growing public reluctance to risk the shot, federal officials abruptly canceled the program Dec. 16.

In the end, 40 million Americans were inoculated, and there was no epidemic. A later, more technically advanced examination of the virus revealed that it was nowhere near as deadly as the 1918 influenza virus. The only recorded fatality from swine flu itself was the unfortunate Pvt. Lewis.