ABSTRACT
Edward Jenner, a country physician in England, noticed that dairymaids who frequently contracted cowpox were often immune to the ravages of smallpox, leading him to develop an approach whereby cowpox was used to vaccinate people against smallpox. The term vaccination is derived from the Latin word vaccinus meaning “from cows.” Vaccination eventually resulted in the complete eradication of smallpox (in 1980) and has been generalized as a reliable method of protection against many pathogens.
