Smallpox was the first widespread disease to be eliminated by human intervention. A highly contagious viral disease, it was endemic in Europe, causing the death of millions of people until the development of vaccination by Edward Jenner around 1800. In many non- European nations, it remained a dreaded, often fatal illness until very recently.

    In May 1966，the World Health Organization ( WHO)，an agency of the United Nations, was authorized to initiate a global campaign to eradicate smallpox. The goal was to eliminate the disease in one decade. At the time, the disease posed a serious threat to people in thirty nations. More than 700 physicians, nurses, scientists, and other personnel from WHO joined about 200，000 health workers in the infected nations to battle the disease. Because similar projects for malaria and yellow fever had failed, few believed that smallpox could actually be eradicated, but eleven years after the initial organization of the campaign, no cases were reported in the field.

    The strategy was not only to provide mass vaccinations but also to isolate patients with active smallpox in order to contain the spread of the disease and to break the chain of human transmission. Rewards for reporting smallpox assisted in motivating the public to aid workers. One by one, each smallpox victim was sought out, removed from contact with and treated. At the same time, the entire village where the victim had. lived was vaccinated.

    By April 1978, WHO officials announced that they had isolated the last known case of the disease, but health workers continued to search for new cases for two additional years to be con^)letely sure. In May 1900, a formal statement was made to the global community. Today smallpox is no longer a threat to humanity. Routine vaccinations have been stopped worldwide.