Medical History Medicine & Health

In 1796 the English physician Edward Jenner, noting that milkmaids who caught cowpox never developed smallpox, inoculated material from a cowpox lesion into a boy named James Phipps, who then resisted exposure to smallpox - the first controlled demonstration of cross-protective immunity. The word vaccine comes from the Latin vacca, meaning cow. Earlier variolation with human smallpox existed, but Jenner's method was safer and scalable, ultimately enabling the WHO-led global campaign that declared smallpox eradicated in 1980, still the only human infectious disease ever eliminated.

Between 1921 and 1922 at the University of Toronto, Banting and Best extracted the pancreatic secretion in Macleod's laboratory, and Collip purified it enough for safe human use. In January 1922, fourteen-year-old Leonard Thompson, dying of type 1 diabetes, received an injection and his blood glucose fell markedly - the first treatment for a previously fatal disease. Banting and Macleod received the 1923 Nobel Prize in Physiology or Medicine, and the discoverers assigned the patent for a symbolic one dollar so insulin could spread quickly; access and price nonetheless remain live global health issues today.

In 1847 Ignaz Semmelweis, working at the Vienna General Hospital, found that mothers delivered by physicians and medical students died of puerperal fever far more often than those attended by midwives, and inferred that doctors were carrying “cadaverous particles” on unwashed hands from the autopsy room. He required handwashing in chlorinated lime solution, and deaths from puerperal fever fell dramatically. Germ theory did not yet exist, so his colleagues rejected the idea, and vindication came only after Pasteur and Lister. WHO's designation of 5 May as World Hand Hygiene Day carries that discovery forward.