An Inquiry into the Causes and Effects of the Variolae Vaccinae: A Disease Discovered in Some of the Western Counties of England, Particularly Gloucestershire, and Known by the Name of the Cow Pox

One doctor noticed that milkmaids who contracted cowpox never caught smallpox. This observation led to one of humanity's greatest breakthroughs. Jenner's groundbreaking text presents his evidence that cowpox - a mild disease passed from horses to cattle to humans - grants complete immunity to smallpox, the plague of its age. Through meticulous case studies and careful observation, Jenner argues for what he calls "the cow pox" as a safer alternative to the dangerous practice of variolation. He documents numerous instances of individuals exposed to smallpox after contracting cowpox, none of whom developed the disease. This slim volume introduced the word "vaccination" to the English language and laid the foundation for the complete eradication of smallpox - achieved in 1980, the only human disease ever eliminated. For readers interested in medical history, scientific reasoning, or the moments when one person's curiosity reshaped the world, this book remains essential.