vaccination (n.) Look up vaccination at Dictionary.com
1800, used by British physician Edward Jenner (1749-1823) for the technique he devised of preventing smallpox by injecting people with the cowpox virus (variolae vaccinae), from vaccine (adj.) "pertaining to cows, from cows" (1798), from Latin vaccinus "from cows," from vacca "cow," a word of uncertain origin. "The use of the term for diseases other than smallpox is due to Pasteur" [OED].