In an effort to educate the public, PBS is streaming a documentary on the 1918 influenza epidemic, and another that reviews the history of the development of the polio vaccine.

American Experience’s Influenza 1918, is currently streaming on The film takes viewers back to September of 1918, when soldiers at an army base near Boston suddenly began to die. The cause of death was identified as influenza, but it was unlike any strain ever seen. As of 1998, it was the worst epidemic in American history, killing over 600,000 — until it disappeared as mysteriously as it had begun.

American Experience’s The Polio Crusade, which will be rebroadcast on March 31 on PBS, and the PBS Video App, pays tribute to an earlier time, when fears of a virus gripped the nation and Americans banded together to conquer a terrible disease. The film interweaves the personal accounts of polio survivors with the story of an ardent crusader who tirelessly fought on their behalf while scientists raced to find a medical breakthrough. Based in part on David Oshinsky’s Pulitzer Prize-winning book Polio: An American Story, the film features an interview with Julius Youngner, the only surviving scientist from the core research team that developed the Salk vaccine.