When the World Health Organization announced in 1980 that smallpox had been eradicated, it was considered a great victory for public health — and as a result, vaccination against smallpox became uncommon. While the eradication of a disfiguring disease is unequivocally good, the increase in poxviruses around the world since then is a curious side effect. The reason? Those with the smallpox vaccine (who are almost entirely older than 40) are more protected against other poxviruses, including monkeypox; those who haven't been vaccinated, which is almost all of the younger population, are less protected.
The variola virus, which causes smallpox, is the only disease to have been eradicated by human medicine. Variola now only exists in two locations in the world in secure laboratories in both Russia and the United States. With millions of recorded deaths attributable to smallpox, the WHO aptly describes it as "one of the most devastating diseases known to humanity." However, it was not the only virus of its kind.
