Born May 17, 1749, in Berkeley; died there Jan. 26, 1823. English physician; discoverer of the smallpox vaccine.

Jenner studied medicine in London, and in 1773 he began an independent medical practice. He observed that milkmaids that had recovered from cowpox were not susceptible to smallpox. On May 14, 1769, he inoculated eight-year-old James Phipps with cowpox, and 1½ months later, with human smallpox; the boy did not become ill. Repeating on Phipps these inoculations over several months and years, Jenner demonstrated the possibility and high effectiveness of vaccinations against smallpox. A smallpox vaccination institute (the Royal Jennerian Society) was founded in London in 1803. Jenner was its first and lifetime director. He was also an honorary member of many academies, universities, and scientific societies of Western European countries.