The man who defeated smallpox

Donald A. Henderson at the Center for Biosecurity in Baltimore

Thirty years ago, on May 8, 1980, a special session of the World Health Assembly in Geneva declared that smallpox had been eradicated. A disease that killed hundreds of millions of people, and haunted humans for more than 3,000 years, had been wiped out. It was the result of a global campaign that took more than a decade. Biological weapons expert Jonathan B. Tucker noted in his 2002 book, Scourge, that "the conquest of smallpox, the first-and so far, only-infectious disease to have been eradicated from nature by human effort, was among the greatest medical achievements of the twentieth century."

The man who spearheaded the smallpox eradication is Donald A. Henderson, now a distinguished fellow with the Center for Biosecurity of the University of Pittsburg Medical Center. Known to most as simply "D. A.," he ran the World Health Organization’s campaign against smallpox for a decade, defying predictions it could not be done, and building an organization and methods that overcame many obstacles to eradication.

The smallpox campaign raised hopes about fighting disease, and helped launch a greatly expanded vaccination effort around the world against other illnesses.  But in an interview at his office in Baltimore last week, Henderson said, "I really have my doubts about a disease being eradicated" today. The reason: the smallpox campaign brought together many factors that are absent in other efforts.

He recalled that smallpox was so severe, killing 2 million people a year, that governments felt they had to act. Also, there was a vaccine that was stable at higher temperatures, "so we didn’t have to worry about refrigeration very much." The program used a unique, inexpensive bifurcated needle that made vaccination far easier. And the smallpox patients always developed a facial rash, making it possible for health workers to spot cases.

Up until 1967, smallpox control and vaccination programs were based solely on mass vaccination. Henderson developed a new strategy of surveillance and weekly reporting that helped identify outbreaks and then respond to them. Two and three-man teams were used to hunt down cases; for every one investigated, they often found 20 or even 100 more. They vaccinated people in a ring around the infected person, and this would often stop the transmission of the disease. Henderson has recounted the story of the smallpox campaign in a memoir published last year, Smallpox: The Death of a Disease.

Henderson’s triumph was later tempered with a nasty discovery. After the collapse of the Soviet Union it was revealed that the Kremlin had created a huge biological weapons program. Among the deadly agents preferred for weapons work was variola, the virus that causes smallpox.

The last samples of the virus, held in the United States and Russia, were to be destroyed in 1999, but a debate erupted over whether they should be retained for future research. The U.S. Defense Department opposed destruction. The issue is still unresolved and being debated anew. Henderson has been a strong advocate for getting rid of the last of the variola virus. "If it is destroyed and is regarded as a crime against humanity to have it, then at least it would be a deterrent," he said. "Anything we can do to deter would be good."

Henderson served in both Bush administrations and Clinton’s, helping set U.S. policy for responding to potential biological threats. He remains worried about the dangers, not only from natural pandemics, but from pathogens that could be released by terrorists to harm populations. He noted the proliferation of relatively sophisticated laboratories that now exist around the world, and the wide availability of information on dangerous agents available on the Internet. "I don’t think there is a moral barrier," holding back terrorists, he said. The tools and competence exist, he added. "It is whether you get motivation and competence together." So far, there has only been one bio attack on the United States, the anthrax mailings of late 2001.

Why? "I’m pretty well persuaded it is luck," he said.