Jenner published An Inquiry into the Causes and Effects of the Variolae Vaccinae in 1798 – perhaps the most influential public health treatise of all time. The importance of Jenner’s work was immediately recognized and although there were sceptics and vicious opponents, vaccination programs began at once. The frequency and ferocity of smallpox epidemics began to decline early in the 19th century, but it remained a menace. In 1949, the American epidemiologist Donald Soper worked out the strategy of containment, i.e. vaccinating all known contacts of every diagnosed case. In 1966, WHO embarked on a campaign to eradicate smallpox. The last naturally occurring case was a girl in Somalia in 1977. In 1980, the World Health Assembly proclaimed that smallpox, one of the most deadly scourges of mankind, had been eradicated. At the beginning of the new millennium, samples of smallpox virus survive in secure biological laboratories in several countries, but thanks to Edward Jenner, this terrible disease need never again take a human life – unless it is used in biological warfare.