Vaccination is the process of giving weakened or dead bacteria or viruses to a healthy person. This provides immunity to a disease. Englishman Edward Jenner coined the term vaccine in the late eighteenth century. He made the first vaccine from a virus affecting cows called the cowpox virus. The virus provided humans with immunity to smallpox, a deadly disease common in the early twentieth century. Smallpox cases were greatly reduced, thanks to Jenner’s vaccine.