Edward Jenner's Smallpox Vaccine
English physician Edward Jenner demonstrated that inoculation with cowpox could prevent smallpox, inventing vaccination and launching the science of immunology.
On May 14, 1796, English country doctor Edward Jenner took material from a cowpox sore on the hand of milkmaid Sarah Nelmes and inoculated it into the arm of 8-year-old James Phipps. Six weeks later, Jenner exposed the boy to smallpox — he did not develop the disease. Jenner published his findings in 1798, coining the term "vaccine" from vacca (Latin for cow). His discovery was initially ridiculed — satirical cartoons showed vaccinated people sprouting cow parts — but its effectiveness was undeniable. Vaccination spread rapidly across Europe and the Americas. Jenner's insight that a mild related disease could confer immunity to a deadly one became the founding principle of immunology and has since saved more lives than any other medical innovation in history.
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