Setting the Scene

Smallpox was a killer: 400,000 Europeans died from it every year. Those who survived were often blinded or scarred for life. But country doctor Edward Jenner noticed something strange: milkmaids who caught cowpox (a mild disease from cows) never seemed to get smallpox. In 1796, he took pus from a cowpox sore on milkmaid Sarah Nelmes and injected it into 8-year-old James Phipps. Six weeks later, he injected James with smallpox. The boy didn't get sick. Vaccination was born — though Jenner had no idea WHY it worked.