Anthrax vaccines known to result in far less scarring, and greatly reduced mortality, in comparison with the naturally acquired disease. The English physician Edward Jenner (1749–1823) had also discovered (1796) the process of vaccination by using cowpox to give cross-immunity to smallpox and by Pasteur's time this had generally replaced the use of actual smallpox material in inoculation. The difference between smallpox vaccination and anthrax or chicken cholera vaccination was that the weakened form of the latter two disease organisms had been "generated artificially", so a naturally weak form of the disease organism did not need to be found. This discovery revolutionized
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