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.