THIS YEAR MARKS THE CENTENARY OF THE SPANISH FLU, which killed between 50 million and 100 million people around the world. That outbreak was the most lethal event of the 20th century, and for 100 years it has spurred researchers to get ahead of the next one.

“It’s always on the mind of today’s physicians,” says Martin Hirsch, a senior physician in the infectious diseases service at Massachusetts General Hospital, and editor in chief of the Journal of Infectious Diseases. Hirsch joins the podcast to discuss what happened in 1918, what tools are on the horizon, and why the modern world may, perversely, be more at risk of a major epidemic.

The podcast also explores a curious footnote to the 1918 outbreak: how it appeared in the newspapers. A wartime culture of censorship kept the worst of the news from appearing in print, especially how influenza spread in the close and unsanitary barracks. Most papers preferred to focus on how the troops were “healthy and thankful for all of the patriotic support,” says Tim Stephens, a health historian who runs the blog The Great Influenza One Day at a Time.

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