Smallpox vaccine, past and present.
D004739:England; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D008512:Medicine in the Arts; D012899:Smallpox / Q000266:history / Q000517:prevention & control; D012900:Smallpox Vaccine / Q000266:history*; D014481:United States
D012900:Smallpox Vaccine