Cowpox

Cowpox is very similar to chicken pox and smallpox, except that it affects cows. Cowpox is significant historically because it was used to create the first smallpox vaccine. This happened because a man named Edward Jenner noticed that milk-maids never got smallpox. He reasoned that this was because they came in contact with cow pox and gained active immunity against smallpox. He tested it with great success but the vaccine was not accepted for many years.

Cow"pox` (--p?ks`), n. Med.

A pustular eruptive disease of the cow, which, when communicated to the human system, as by vaccination, protects from the smallpox; vaccinia; -- called also kinepox, cowpock, and kinepock.

Dunglison.

© Webster 1913.