HEALTH

The Eradication of Smallpox

1980 CE

History · Contemporary · Holocene · Meghalayan

On 8 May 1980, the World Health Assembly declared smallpox eradicated, two and a half years after the last natural case, diagnosed in Somalia in 1977.

The eradication of smallpox is declared by the World Health Assembly on 8 May 1980, about two and a half years after the last natural case, diagnosed in Somalia in 1977. The global campaign conducted by the World Health Organization did not rest on mass vaccination alone: where that did not suffice, it relied on surveillance and containment, that is, active case finding, a reward for reporting, and ring vaccination, which consists in immunising the contacts of each case so as to deprive the virus of susceptible subjects. The disease had caused several hundred million deaths over its last century.

Why it matters

Smallpox remains the only eradicated human disease, and three properties made it accessible. It infected only humans, with no animal reservoir; it did not pass unnoticed, every contagious person presenting a characteristic rash; and the vaccine conferred solid and durable protection. No other human disease combines these three conditions, which explains why the result has not been reproduced. The campaign moreover constitutes the most complete precedent of international health cooperation, conducted between states otherwise opposed.

Dating & uncertainty

Certification occurs on 8 May 1980. Field staff operated in more than thirty countries where the disease still persisted at the beginning of the campaign.

Our species’ history as one day

23:59:4712.6 s before midnight

if the 315,000 years of Homo sapiens were compressed into a single day