Skip to Main Content

There are few people in the field of global public health so well-known that you merely need to utter two initials to evoke instant recognition.

But to raise in conversation Dr. Donald Ainslee Henderson, the man who led the successful effort to eradicate smallpox, all anyone ever bothered to say was “D.A.”


Henderson, a few weeks shy of his 88th birthday, died late Friday of complications that arose after he recently fractured a hip.

Towering in physical stature as well as in reputation, Henderson had a booming voice, which he used to great effect. He did not hesitate to express his views — even if they were not shared by others.

“D.A. was a giant intellectually, he was a giant in his personality, and he didn’t shy away from controversy,” said his friend Michael Osterholm, director of the University of Minnesota’s Center for Infectious Diseases Research and Policy.


Dr. Bill Foege, a friend and colleague for over 50 years, agreed.

“He was a person of strong convictions,” said Foege, who served as director of the Centers for Disease Control and Prevention from 1977 to 1983 and who first met Henderson at the CDC in 1962.

“I always think that was one of the attributes that provided for leadership because people don’t like to follow someone who’s uncertain about where they’re going. He brought a certain certainty to everything he did.”

Before taking the lead in the smallpox eradication program, Henderson was the CDC’s director of disease surveillance. His mentor had been Alexander Langmuir, the epidemiologist who founded the CDC’s renowned program to train disease detectives.

“I remember with Alex once talking about a subject and he presented his side and I said: ‘But it’s worth looking at the other side,’” Foege recalled. “And he slammed his fist down on his desk and said ‘There is no other side.’”

“D.A. got part of his training in this environment of absolute certainty.”

Henderson also shared Langmuir’s core belief that good surveillance is crucial to disease control.

“He always stressed the fact that without comprehensive disease surveillance, you just couldn’t run an effective public health program,” said Osterholm.

Tapped to lead the smallpox eradication program in 1966, Henderson moved to the World Health Organization, working as chief medical officer for the program.

In 1977 the world saw its last case of wild smallpox infection — a few cases infected through lab accidents happened later — and the disease was declared eradicated in 1980. To this day smallpox remains the only human disease ever eradicated.

The project had been an 11-year grind, and rather than being buoyed by that extraordinary achievement, it left Henderson deeply skeptical of other eradication efforts.

Though he held out hope for the prospects of Guinea worm eradication, Henderson argued other diseases were out of reach.

“He was very impatient with people claiming that they were going to be able to eradicate this, that, and the other thing,’’ said Dr. Donald Hopkins, special adviser to the Guinea worm eradication program.

Hopkins, formerly with the CDC, worked on the smallpox program as it neared its successful completion. “I really, really regret that he didn’t get to see the end of Guinea worm,” he told STAT.

Henderson’s pessimism about eradication prospects extended to the effort to rid the world of polio, though in 2011 he told the New York Times he’d come to conclude that the job might get done.

Still, in a speech he gave the next year, he appeared to revert to his previous pessimism. Those remarks, fleshed out with correspondence, were published as a Q&A in the Philosophical Transactions of the Royal Society B in 2013.

“Smallpox eradication proved to be infinitely more difficult than I or anyone else had imagined it would be,” Henderson explained, citing the problems posed by floods, wars, famines, and the mass movement of refugees, to say nothing of obstacles thrown up by inflexible bureaucracies of governments and “a sclerotic WHO administration.”

“The program was ultimately successful but success hung in the balance on many occasions.”

For years, Henderson created headaches for those running the polio eradication program, calling repeatedly for the expensive and long-overdue effort to refocus on containing polio at low levels rather than trying to snuff it out entirely.

”I think we have to recognize that … the odds on succeeding are long. Maybe not impossible, but they’re very, very remote,” Henderson said in an interview with this reporter in 2005.

”There’s no reason why you can’t maintain a control program which is going to be far less expensive than trying to maintain an eradication . … I look upon this and think: This isn’t the end of the world.”

Opponents of Henderson’s suggestion insisted it was costing billions of dollars to keep polio cases at low levels. Letting go of the goal of eradication would threaten that funding, and the disease would come roaring back.

After the completion of the smallpox program, Henderson moved into academia, becoming dean of the Johns Hopkins School of Public Health in Baltimore in 1977.

He served as associate director of the US government’s Office of Science and Technology Policy, deputy assistant secretary for Health, and director of the Office of Public Health Emergency Preparedness.

In recent years he worked in the University of Pittsburgh Medical Center’s Center for Health Security, a position he held until his death.

Henderson was known for his doggedness. “When he would pursue something, he would really pursue it. And he wouldn’t give up until he had clearly been defeated or he won,” Foege said.

But perhaps less well-known was his concern for public health workers dispatched by organizations like the CDC or the WHO to far-flung places before the days of cellphones and email, when a letter home might take weeks to arrive.

“I don’t know how many stories I heard over the years [where] … a parent would actually call D.A. in Geneva and ask if he could check up on their child,” said Foege.

“And he would do that because he understood this was important to success, to protect your field people.”