Edward Jenner Demonstrates the Smallpox Vaccine

English physician Edward Jenner (1749–1823) inoculated eight-year-old James Phipps with matter from a cowpox lesion on milkmaid Sarah Nelmes on May 14, 1796, then demonstrated Phipps was protected against smallpox exposure. Jenner published his findings in 1798, coining the term vaccination from the Latin for cow. Smallpox had killed an estimated 400,000 Europeans annually and carried a 30% fatality rate. His method pioneered the entire field of immunology and vaccination, ultimately leading to the WHO's declaration of smallpox eradication in 1980 — the only human disease ever eliminated.