Edward Jenner

person · earth · Berkeley, Gloucestershire, England

English physician and naturalist (1749–1823) who on 14 May 1796 inoculated the eight-year-old James Phipps with material from a cowpox lesion on the hand of the dairymaid Sarah Nelmes, then challenged him with smallpox matter and found him protected. Jenner did not discover the folk observation that cowpox protected against smallpox — it was current among dairy workers, and Benjamin Jesty had inoculated his family with cowpox in 1774 — but he tested it, published it, and campaigned for it, which is why the practice spread. His 1798 Inquiry gave the procedure the name vaccination, from vacca, cow. He had no theory of immunity and no notion of a virus; the mechanism he was exploiting was not understood for well over a century.