SMALLPOX — THE DEADLIEST KILLER IN HUMAN HISTORY

500 million people killed in the 20th century alone. More than both World Wars combined. A virus that infected humans for 3,000 years — from the mummy of Ramesses V to a hospital in Birmingham in 1978. And then, on May 8th, 1980, it was gone. The only disease humanity has ever deliberately hunted to extinction. In this video: → How one infected Spanish soldier in 1520 killed half the Aztec Empire → The vaccine discovered by accident watching dairy farmers → Why Napoleon freed a British prisoner specifically because of Edward Jenner → The last person to die of smallpox — one year AFTER it was declared eradicated → Two vials of live smallpox still exist today. The debate over destroying them has not been resolved.