Smallpox vaccine

Patent Granted Smallpox vaccine, the first successful vaccine to be developed, was introduced by Edward Jenner in 1798. He followed up his observation that milkmaids who had previously caught cowpox did not later catch smallpox by showing that inoculated cowpox protected against inoculated smallpox. The word vaccine is derived from Variolae Vaccinae (i.e. smallpox of the cow), the term devised by Jenner to denote cowpox and used in the long title of his Inquiry into the...Variolae Vaccinae... known...[as]... the Cow Pox.