Smallpox - Countdown to Zero | AMNH A deadly viral infection that once killed millions of people every year.

#vaccines #naturalimmunity #VaccineQuestions Smallpox Was Eradicated by Vaccines—Not "Natural Immunity"
💉 The last known case of smallpox was in 1977. Before vaccines, it killed 300 million people in the 20th century alone. www.amnh.org/explore/scie...