Edward Jenner, FRS FRCPE 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 1796 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". In Jenner’s time, smallpox killed around 10 percent of the population, with the number as high as 20 percent in towns and cities where infection spread more easily. In 1821 he was appointed physician extraordinary to King George IV, and was also made mayor of Berkeley and justice of the peace. 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.