Jenner called the technique vaccination, as vacca was the Latin word for “cow.” Cowpox vaccination was superior to smallpox variolation in that the vaccine from the less dangerous cowpox disease didn’t kill anybody but still provided immunity. This was the first building block on the road to safe vaccines, which have since been developed for many life-threatening diseases. Polio. Measles. Meningitis. Diphtheria. We’ve triumphed over them all.
