[The beginnings of vaccine diffusion in France (1800-1850)].

First factor of mortality at the eighteenth century, smallpox killed each year about 50.000 to 80.000 people in France and 25.000 to 30.000 in England. In 1796, Edward Jenner discovered the fabulous properties of the cowpox which, transplanted from cow to human, immunized against the disease. In France, between 1800 and 1850, a few hundreds of vaccinators took part in a significant crusade against smallpox. They went in the villages and the thatched cottages, fought against the routine, and, sometimes, against the hostility of the mayors or the priests. Moreover, the cow-pox often missed or lost its strength. Despite everything, their efforts were crowned success: during the nineteenth century, small-pox mortality drops by 90%.