Eradicating Smallpox

A viral infection, smallpox spread along trade routes in Africa, Asia, and Europe, reaching the Americas in the 16th century. Because smallpox requires a human host to survive, it smoldered in densely populated areas, erupting in a full-blown epidemic every ten years or so. Wherever it appeared, smallpox caused blindness, sterility, scarring, and death.

In Africa and Asia, smallpox was traditionally contained through variolation—deliberately infecting an individual with a controllable case of smallpox to confer lifelong immunity. Variolation spread from Asia and Africa into Europe and the Americas during the 18th century. This practice had its dangers, as recipients of variolation could develop a full-blown case of smallpox.

In 1798, the English physician Edward Jenner developed a safer technique: vaccination with cowpox (vacca is the Latin word for cow). He based his “discovery” on existing folk knowledge but provided scientific proof of its veracity by testing the vaccine on a young child.

In 1809, following Jenner’s published account of his success in using vaccination to prevent smallpox, the town of Milton, Massachusetts, offered free vaccination to all its inhabitants. Over three hundred persons were inoculated during a three-day campaign in July. The town leaders then took the daring step of holding a public demonstration to prove without a doubt that cowpox vaccine offered protection from smallpox. In October, twelve children, selected from those vaccinated in July, were inoculated with fresh, virulent smallpox matter. Fifteen days later, they were discharged with no sign of smallpox infection. The experiment’s success led Miltonians to declare “He is Slain,” presaging the idea of “slaying” smallpox permanently.

During the mid-19th century, states began to mandate vaccination for schoolchildren. In response, instrument makers developed and patented a variety of ingenious vaccinators. Many of these instruments used a trigger mechanism; health care providers squeezed the trigger, releasing the needle and vaccine. Physicians, who earned a small fee for vaccinating, also performed arm-to-arm vaccination, scraping pus from a vaccinated arm to use on another patient.

After the Civil War, arm-to-arm vaccination became less common. Instead, cowpox was often harvested directly from cows and dried on ivory points such as these. Physicians used ivory points and might carry vaccine in a scab carrier like this one that belonged to a physician in Baltimore.

As the threat of smallpox receded, people sometimes became complacent and vaccination rates declined. When this occurred, smallpox epidemics often emerged, with the result that entire communities then rushed to be vaccinated. The last smallpox outbreak in the United States occurred in New York City in 1947. Public health experts arrested the outbreak in a matter of a few weeks with only two deaths, thanks to their moving quickly to vaccinate nearly 6 million New Yorkers.

Although smallpox had not yet been “slain,” as the citizens of Milton had so confidently proclaimed in 1809, the disease was on its deathbed by the mid-20th century. In 1958, the World Health Organization committed to eradicating the disease worldwide.

D. A. Henderson, a lead epidemiologist associated with the WHO smallpox eradication campaign, donated many of the objects he collected during the campaign to the National Museum of American History.

Among these objects are smallpox deities from the Indian subcontinent and the Yoruba people of Nigeria. Shapona, the Yoruba god, nurtured humans, giving them the grains that sustained life, but he also used smallpox (which caused granular pustules) to punish people. Henderson and other public health experts received these statues at a WHO conference. Sheetala (Śītalā), the smallpox goddess from the Indian subcontinent, used smallpox to chastise humans when they refused to worship her. When humans agreed to acknowledge her, she healed smallpox sufferers and even resuscitated those who had died.

Bi-furcated needles were incredibly easy to use and required less vaccine than other methods of vaccination. Best of all, these needles could be sterilized and re-used. Wyeth Laboratories, which had developed the bi-furcated needle, waived their royalties.

In 1967, WHO workers vaccinated 25 million people but many people in susceptible areas remained unvaccinated. Eradication Escalation (E2) now focused on containing smallpox outbreaks during October, the natural seasonal low point of smallpox transmission. Prevention of just one case during this period could permanently destroy a smallpox chain. E2’s success in breaking smallpox chains made eradication possible.

In 1980, the WHO proclaimed, “Smallpox is dead!” During the early 2000s, fears that terrorists might seize samples of the smallpox virus from a controlled laboratory and release it led the United States to reinvest in smallpox vaccine. These fears proved unfounded, and the replenished stocks of smallpox vaccine languished unused.

Today, not only these vaccines but smallpox itself has been relegated to history.