DRAFT - Awaiting COP Review and Approval: The evolution of and background behind the naming of illnesses and the development of medical terminology is often very fascinating. Edward Jenner coined the term vaccination in 1803 while the French physician, Pierre Bretonneau, first called the now Diphtheria, diphtérite in 1826. Jenner spread the term vaccination, originating from the latin word for cow (vacca), after he tested the linkages between smallpox and cowpox and found that those exposed to the less deadly cowpox developed immunity against the similar but more lethal smallpox. Bretonneau’s argued that the term diphtérite, rooted in the Greek words “leather” and “hide”, accurately described the coating that appears in the throat when someone is infected. Like the history of many words, some of this vocabulary originated from the specific disease characteristics and symptoms while other terms are less rooted in practical meaning and more in one’s tales associated with the word, as was the case with Jenner.