Distinctive cowpox (click here) lesions appeared on the boy's hands, arms and feet
Edward Jenner (1749-1823), (click here) an English doctor, became interested in the idea that previous illness with a disease called cowpox could protect a person from later becoming ill with smallpox. Jenner's biographer claimed that Jenner heard this folk wisdom from a milkmaid: having caught cowpox from a cow, she believed herself, and her smooth skin, safe from smallpox.
Cowpox is an uncommon illness in cattle, usually mild, that can be spread from a cow to humans via sores on the cow. During an infection, dairy workers may have pustules on their hands. Sufferers can spread the infection to other parts of the body.
We know now that the cowpox virus belongs to the Orthopox family of viruses. Orthopox viruses also include horsepox virus, monkeypox virus and variola viruses, which cause smallpox.
