In celebration of the 200th anniversary of Edward Jenner's Inquiry into the causes and effects of the variolae vaccinae.

This review commemorates the 200th anniversary of Edward Jenner's development of a vaccine for variola, the cause of smallpox, and the 20th anniversary of its eradication. Jenner's original 23 case reports are briefly revisited within the context of earlier attempts to prevent this dreaded disease and in light of the current understanding of vaccinology and immunology. In addition, with molecular biological information available about many pox viruses and detailed sequence knowledge of some, it is now possible to appreciate Jenner's prescient accomplishments more fully.