Smallpox Eradicated: Last Natural Case Confirmed

Ali Maow Maalin, a 23-year-old hospital cook in Merca, Somalia, developed the telltale rash of variola minor on October 26, 1977, and became the last person on Earth to contract smallpox through natural transmission. He survived. The disease that had killed an estimated 300 million people in the twentieth century alone, more than all the century's wars combined, was finished. The World Health Organization's Intensified Eradication Program, launched in 1967 under the direction of American epidemiologist Donald Alas Henderson, had pursued the virus across every continent for a decade. The strategy was not mass vaccination, which would have been logistically impossible in remote regions of Africa and South Asia, but "ring vaccination": identify every new case, isolate the patient, and vaccinate every person within the surrounding area to break the chain of transmission. Teams traveled by jeep, helicopter, camel, and canoe to reach villages that had never seen a doctor. By the early 1970s, smallpox had been eliminated from South America, Asia, and most of Africa. The final holdouts were Ethiopia, where civil war complicated access, and Somalia, where nomadic populations moved across borders constantly. Maalin's case was traced to contact with two children he had escorted to a hospital. WHO teams vaccinated everyone in his district. When no new cases appeared after weeks of surveillance, epidemiologists began to believe they had reached the end. The WHO waited two full years after Maalin's recovery before declaring victory, maintaining global surveillance to ensure no hidden cases remained. On May 8, 1980, the World Health Assembly formally certified that smallpox had been eradicated, the first and still only human disease to be deliberately eliminated from nature. The eradication of smallpox remains the single greatest achievement in the history of public health. The campaign cost approximately $300 million over thirteen years, a fraction of what a single year of continued vaccination would have cost. Samples of the virus survive today in two high-security laboratories in the United States and Russia, and whether to destroy them remains one of the most contentious questions in bioethics.