The eradication of smallpox.
D001459:Bangladesh; D005002:Ethiopia; D049690:History, Ancient; D049691:History, Medieval; D049711:History, Modern 1601-; D006801:Humans; D009549:Nigeria; D012899:Smallpox / Q000453:epidemiology / Q000266:history / Q000517:prevention & control; D014611:Vaccination