Edward Jenner and the Smallpox Vaccine (1796)
Smallpox was one of history's biggest killers until a country doctor named Edward Jenner made a brilliant observation. He noticed that milkmaids who caught cowpox from cows never got smallpox.
In 1796, Jenner tested his theory by deliberately infecting a boy with cowpox, then exposing him to smallpox - the boy stayed healthy! He published his findings in 1798, creating the world's first vaccination.
Parliament was so impressed they gave Jenner £10,000 in 1802 to open a vaccination clinic. By 1840, smallpox vaccination was free for babies, and it became compulsory in 1853. However, many people resisted vaccination because they were terrified of catching diseases from cows!
Amazing Impact: Jenner's vaccination method prevented around 3,500 deaths by 1751 and eventually eliminated smallpox completely.