Smallpox was endemic to Europe, Asia and Arabia for centuries, a persistent menace that killed three out of ten people it infected and left the rest with pockmarked scars.
“There hasn’t been a kill off in human history to match what happened in the Americas—90 to 95 percent of the indigenous population wiped out over a century,” says Mockaitis. “Mexico goes from 11 million people pre-conquest to one million.”
Centuries later, smallpox became the first virus epidemic to be ended by a vaccine.
