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
History of smallpox identified as smallpox. Early in history, it was observed that those who had contracted smallpox once were never struck by the disease again. Thought to have been discovered by accident, it became known that those who contracted smallpox through a break in the skin in which smallpox matter was inserted received a less severe reaction than those who contracted it naturally. This realization led to the practice of purposely infecting people with matter from smallpox scabs in order to protect them later from a more severe reaction. This practice, known today as variolation, was first practiced in China in the