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
Smallpox death rate of infants in Russia may have been even higher. The widespread use of variolation in a few countries, notably Great Britain, its North American colonies, and China, somewhat reduced the impact of smallpox among the wealthy classes during the latter part of the 18th century, but a real reduction in its incidence did not occur until vaccination became a common practice toward the end of the 19th century. Improved vaccines and the practice of re-vaccination led to a substantial reduction in cases in Europe and North America, but smallpox remained almost unchecked everywhere else in the world. In