Smallpox prevention has a longer history than Edward Jenner’s famous 1796 experiment. Practices now grouped under variolation were used in parts of Asia, Africa and the Ottoman world before becoming established in Britain and North America.
Variolation deliberately exposed a person to smallpox material in an attempt to produce a less severe infection followed by immunity. It could reduce risk compared with naturally acquired smallpox in some settings, but it still caused illness, could be fatal and could transmit smallpox to others.
Jenner tested whether exposure to cowpox could protect against smallpox and published his observations in 1798. His work helped promote a safer approach that came to be called vaccination, although the history includes earlier observations and experiments by others and later changes in vaccine production.
Modern ethical standards would not permit Jenner’s experiment on James Phipps to be conducted in the same way today. Historical importance should not be confused with modern research ethics.
Smallpox eradication was ultimately achieved through vaccination, surveillance, case detection and coordinated public-health work across many countries. The World Health Organization declared smallpox eradicated in 1980.
