Once the most feared disease on the planet, smallpox killed countless people in the course of human history. The first signs of smallpox are fever and aches. Then come the disfiguring pustules, often followed by death. But there hasn’t been a case in nearly 30 years. In 1979, after an aggressive 12-year campaign of vaccination, the World Health Organization declared human beings smallpox-free. William Foege, who worked on the effort and is now a senior fellow at the Bill and Melinda Gates Foundation, says smallpox is still the only disease that humans have ever managed to vanquish.
Crude versions of a smallpox vaccine were first described in the 18th century, and by the 19th century, vaccination had become widespread—and in some countries, compulsory. “The speed with which smallpox disappeared was breathtaking,” Foege says.
Smallpox hasn’t vanished entirely, however. At least two laboratories—the CDC in Atlanta and one in Moscow—keep the virus alive, and the last known case, in 1978, arose from a lab accident in Birmingham, England. Although the manufacture of smallpox vaccine for the general public was suspended in 1982, production resumed when security analysts realized that smallpox would be a choice weapon for bioterrorists. In 2002, President George W. Bush claimed that the United States had stockpiled enough smallpox vaccine to protect the entire country.
If smallpox does reappear, “scientifically, we know how to stop outbreaks,” Foege says. “My concern would be the social chaos of people who are trying to get in line for vaccinations.”