The year 1996 marked the two hundredth anniversary of Edward Jenner's first experimental vaccination--that is, inoculation with the related cow-pox virus to build immunity against the deadly scourge of smallpox.
Edward Jenner (1749-1823), after training in London and a period as an army surgeon, spent his whole career as a country doctor in his native county of Gloucestershire in the West of England. His research was based on careful case-studies and clinical observation more than a hundred years before scientists could explain the viruses themselves. So successful did his innovation prove that by 1840 the British government had banned alternative preventive treatments against smallpox. "Vaccination," the word Jenner invented for his treatment (from the Latin vacca, a cow), was adopted by Pasteur for immunization against any disease.
In the eighteenth century, before Jenner, smallpox was a killer disease, as widespread as cancer or heart disease in the twentieth century but with the difference that the majority of its victims were infants and young children. In 1980, as a result of Jenner's discovery, the World Health Assembly officially declared "the world and its peoples" free from endemic smallpox.