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 intensive care units, anesthesiologists, and health care workers in other settings who would be crucial first-line responders in the event of a bioterrorist attack using smallpox. Many healthcare workers refused, worried about vaccine side effects, but many others volunteered. It is unclear how many actually received the vaccine. In 2002, the Israeli Army, in a similar attempt at mass vaccination, found many soldiers unwilling to volunteer. In May 2007, the Vaccines and Related Biological Products Advisory Committee of the FDA voted unanimously that a new live virus vaccine produced by Acambis, ACAM2000, is both safe and effective for use in