
Ring Vaccination: The Strategy That Ended Smallpox Worldwide
In May 1980 the WHO formally declared smallpox eradicated after a 13-year, roughly $300 million vaccination drive that used a ‘ring vaccination’ approach—targeting contacts around each case rather than mass vaccination—pioneered by Donald Henderson and William Foege. The last naturally acquired case was Ali Maow Maalin in Somalia (1977), with the final global case in a laboratory-related incident (Janet Parker, 1978). By the late 1970s the disease had been eliminated from most regions (South America by 1971, Indonesia 1972, India 1975, Bangladesh 1975, Ethiopia 1976), though continued lab stocks existed in two secure facilities (CDC in Atlanta and VECTOR in Koltsovo) and remain the subject of ongoing debate about destruction and biosecurity.













