Edward Jenner, FRS was an English physician and scientist who was the pioneer of smallpox vaccine, the world's first vaccine. The terms "vaccine" and "vaccination" are derived from Variolae vaccinae, the term devised by Jenner to denote cowpox. He used it in 1798 in the long title of his Inquiry into the...Variolae vaccinae...known...[as]...the Cow Pox, in which he described the protective effect of cowpox against smallpox. Jenner is often called "the father of immunology", and his work is said to have "saved more lives than the work of any other human". A member of the Royal Society, in the field of zoology he was the first person to describe the brood parasitism of the cuckoo. In 2002, Jenner was named in the BBC's list of the 100 Greatest Britons.

https://en.wikipedia.org/wiki/Edward_Jenner