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
Mozart and smallpox increased crowding, making it easier for the disease to spread; yet effective protection from smallpox through a smallpox vaccine was discovered only at the end of the century (see below). The disease was a terrible one for its victims. Ian and Jenifer Glynn write: So what was it like? As children, we were told it was like chickenpox but worse. In fact it is not related to chickenpox, and it was unimaginably worse. In an unvaccinated population, something like 10–30 percent of all patients with smallpox would be expected to die. And dying was not easy; smallpox was, as Macaulay