The idea and the experiment.
Warren
P
P
D002648:Child; D015605:Cowpox / Q000266:history / Q000517:prevention & control; D049671:History, 18th Century; D006805:Human Experimentation / Q000266:history*; D006801:Humans; D012899:Smallpox / Q000266:history / Q000517:prevention & control; D014612:Vaccines / Q000266:history*
D014612:Vaccines