Vaccines, Logistics and the End of Smallpox

Smallpox is the only human disease ever eradicated. It killed an estimated 300 million people in the twentieth century alone. In 1967 the World Health Organization launched an intensified eradication programme. Early mass vaccination was difficult in poorer regions, so teams adopted 'surveillance and containment', also called ring vaccination: finding each case quickly and vaccinating everyone around it.

The programme required cooperation across Cold War divides, with the Soviet Union donating large quantities of vaccine and the United States contributing funding and expertise. Local health workers in countries such as India, Bangladesh and Ethiopia did much of the work. The last natural case occurred in Somalia in October 1977, and the World Health Assembly declared smallpox eradicated in May 1980. Success depended on the disease's features, including no animal reservoir and visible symptoms, as well as on international cooperation.