Vaccination disease people tried to prevent by inoculation and was the first disease for which a vaccine was produced. The smallpox vaccine was invented in 1796 by English physician Edward Jenner and although at least six people had used the same principles years earlier he was the first to publish evidence that it was effective and to provide advice on its production. Louis Pasteur furthered the concept through his work in microbiology. The immunization was called "vaccination" because it was derived from a virus affecting cows ( 'cow'). Smallpox was a contagious and deadly disease, causing the deaths of 20–60% of
Smallpox vaccine persons at high risk of exposure to smallpox virus. However, due to the high rate of serious adverse effects, the vaccine will only be made available to the CDC (a part of the United States Department of Health and Human Services) for the Strategic National Stockpile. The mortality of the severe form of smallpox—"variola major"—was very high without vaccination, up to 35% in some outbreaks. A method of inducing immunity known as inoculation, or "variolation" was practiced before the development of a modern vaccine and likely occurred in Africa and China well before the practice arrived in Europe. It may