IMMUNOLOGY

Detailed explanation-1: -The term “vaccine” is derived from the Latin word “vaccinus”, from “vacca”, which means “from cows”. Edward Jenner coined the term for the technique where, he injected individuals with a mild form of cowpox, thereby rendering them immune to smallpox.

Detailed explanation-2: -The smallpox vaccine, introduced by Edward Jenner in 1796, was the first successful vaccine to be developed. He observed that milkmaids who previously had caught cowpox did not catch smallpox and showed that inoculated vaccinia protected against inoculated variola virus.