title: Goodbye to smallpox; a historical background.
mesh_terms: D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049690:History, Ancient; D049691:History, Medieval; D006801:Humans; D007114:Immunization / Q000266:history*; D012899:Smallpox / Q000266:history*