Smallpox was eradicated worldwide after a global vaccination campaign led by the WHO.
The World Health Organization intensified its global smallpox eradication program in 1967. The campaign combined mass vaccination with surveillance and containment: health workers searched for cases, traced contacts, and vaccinated people around outbreaks. This approach was especially valuable in places where vaccinating every person was difficult.
The last naturally occurring case of variola major, the more severe form, was recorded in Bangladesh in 1975. The final naturally acquired case of any smallpox infection occurred in Somalia in 1977. After reviewing the evidence, the WHO officially declared smallpox eradicated in 1980.
Smallpox is the only human infectious disease officially eradicated so far. Polio remains the subject of eradication efforts, but it has not been certified eradicated worldwide. Smallpox vaccination is no longer routinely given to the general public because natural transmission has stopped, although virus samples remain secured in specialized laboratories.