Jenner and vaccination
Deliberate infection with a mild disease gives protection against a lethal one.
- When
- Known to
- ± 1 year
- Era
- Early Modern, Holocene
Observing that milkmaids who caught cowpox did not get smallpox, Jenner inoculates a boy with cowpox in 1796 and then exposes him to smallpox, which does not take. Variolation using smallpox itself had long been practised in China, India, Africa and the Ottoman world and was introduced to Britain by Lady Mary Wortley Montagu; Jenner's contribution is the safer cowpox method and its systematic promotion. Smallpox is the only human disease ever eradicated.