Etymology: vaccine

Believe it or not, this word actually relates to cows!  Don’t worry, I’ll explain.  The Latin name for the cowpox virus is variolae vaccinae, which comes from Latin, vaccinus, meaning, “from or pertaining to cows.”  The word vacca, in Latin, means “cow” and no one is sure of its origin.  Incidentally, the English word cow is a very old word dating back to the PIE root gwou- and is pretty much the same in all Germanic languages.  Anyway back to vaccine!  Smallpox was a very big problem for humans prior to around 1800.  It was observed that milkmaids, due to having been exposed to a similar but much less deadly infection called cowpox, had developed an immunity to smallpox. British physician Edward Jenner accidentally invented the vaccine by injecting people with the cowpox virus, or vaccinae, making them immune to smallpox as well.

The word wasn’t used in reference to other diseases until Louis Pasteur, inventor of the rabies vaccine, started doing so.  Incidentally, Pasteur also invented pasteurization, and thus the word pasteurize is simply Pasteur’s surname with -ize added to it.  His surname is French and means, “pastor.”

Speaking of Louis Pasteur, when I was a kid, I remember seeing a video, or maybe it was just a book, where Louis Pasteur is explaining what a vaccine is to a young boy.  I remember he said that it’s like a bunch of soldiers are marching into your body to protect you from diseases.  I have been unable to track down this book or video, so if anyone else remembers this and can shed some light on it, that’d be awesome!