Explanation:

• Edward Jenner was an English physician who was a contributor to the development of the smallpox vaccine.  

• Then terms vaccine and vaccination are derived from Variolae vaccinae (smallpox of the cow), 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.