THE WORLD ATLAS

Science · 1796

Jenner's smallpox vaccine: the first vaccination

Berkeley, Gloucestershire (England)

Edward Jenner, a country doctor in Berkeley, Gloucestershire, suspected that the pus from cowpox blisters, a mild disease caught from cows, protected people against smallpox. On 14 May 1796 he scraped material from the cowpox blisters of a milkmaid, Sarah Nelmes, into two small cuts on the arm of James Phipps, the eight-year-old son of his gardener; when Jenner later exposed the boy to smallpox matter, he did not fall ill.

Jenner published his results in 1798, and his Latin name for cowpox, variolae vaccinae, gave us the words vaccine and vaccination.

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Why it mattered

Smallpox killed about 30 percent of the people it infected and is estimated to have killed up to 300 million people in the 20th century alone; vaccination campaigns, finished by a WHO global programme, wiped it out, and in 1980 smallpox became the only human disease ever eradicated. Jenner's idea of training the body's defences in advance grew into the vaccines that, by a 2024 WHO-led estimate, have saved at least 154 million lives in the past 50 years, 101 million of them infants.

Elsewhere

An older and riskier method, variolation (infecting people with material from a mild case of smallpox itself), had been practised in China from around the 1500s and reached Europe from Asia in the early 18th century; Jenner himself was variolated as a schoolboy.

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