The word "unprecedented" has been used frequently crisis to describe the ongoing pandemic, but Professor Frank Snowden, professor of history of medicine at Yale University and author of Epidemics and Society: From the Black Death to the Present, disagrees with this characterization. Snowden tells Pedro da Costa about how pandemics have imperiled societies, ranging from The Plague of Athens, to the Black Death, to the 1918 Spanish Flu. He traces how infections across history have shaped human destinies and identifies repeatable patterns in how they affect societies. Filmed on May 7, 2020.