English physician, renowned as the originator of vaccination. Born at Berkeley, Gloucestershire, he became a resident pupil of John Hunter in London and while there arranged the specimens brought back by Captain Cook from his first voyage. In 1773 he returned to his birthplace to practise medicine. During the next twenty years his observation of smallpox cases seemed to confirm the local belief that dairymaids who contracted cowpox (the milder bovine form of the disease) were immune. This led him to inoculate a boy of 8 with lymph taken from cowpox sores (1796). Jenner's account of this and subsequent successful vaccinations was published in his Inquiry into the Causes and Effects of the Variolae Vaccinae (1798). A number of leading physicians soon declared their acceptance of the idea and the opposition of the majority of other doctors was overcome when the number of deaths from smallpox fell by about two thirds in less than a decade. Parliament awarded him a grant of £30,000 for his discovery which was rapidly taken up throughout the world.