Edward Jenner (1749 - 1823) was a brilliant English doctor and researcher who was responsible for the discovery of vaccination against smallpox as a method to defeat infectious diseases by preventing the contagion of healthy subjects. On May 14, 1796, Jenner inoculated into the arm of an 8-year-old boy a small amount of purulent material taken from the wounds of a woman suffering from smallpox Vaccino, the form of smallpox that affected cattle and - in a mild form - also farmers. The child had no trouble and Jenner demonstrated that the child had become immune to the human form of smallpox. This practice was given the name of vaccination.