Smallpox was one of the deadliest diseases in human history; the virus killed up to an estimated half a billion people in the 20th century alone. In the 1970s, the World Health Organization undertook a massive eradication campaign, and by 1979, the agency officially declared the end of smallpox.

That story and what lessons it might have for how we manage diseases today is the subject of the latest dispatch from our friends at Retro Report.

Umbreen Butt is a producer for Ikana Media and was a freelance producer for Retro Report on this documentary.