Man versus virus

Donald Ainslie (“D.A.”) Henderson, epidemiologist, died on August 19th, aged 87

THE DIRECTOR of the World Health Organisation knew the plan would fail. To rid the world of smallpox was impossible. Each year, 2m people still died of it. Total global vaccination was a chimera. Besides, no disease had ever been eradicated. But since he had been pushed into it by the Soviet Union and the United States, he would put an American at the head of it, so that when everything went down the tubes it would be America’s fault. The year was 1966; he asked for Donald Henderson.

In terms of revenge, he picked wrong. D.A., as everyone called him, was not at all inclined to fail. Brawny, brimming with confidence and not a sufferer of fools, he was already fixed on smallpox. He dated his obsession to 1947, when in supposedly smallpox-clear New York a man visiting from Mexico died of the disease, 12 others caught it, and the city went wild with fear—that ageold fear of a disease that killed a third of its victims, had ravaged the native tribes of the Americas, and left the faces of survivors gouged with scars.

After that, he had no interest in any old dull doctor’s life. He wanted to study the causes, spread and suppression of epidemics. Rather than serve in the army he joined the Epidemic Intelligence Service at the Communicable Disease Centre in Atlanta, for what he called “firefighter” training. As soon as a disease broke out anywhere in the world, he would dash to tackle it—becoming a proper “shoe-leather” epidemiologist, as opposed to a “shiny-pants” desk-bound sort. When he was hauled away from his antismallpox work in west Africa and sent to Geneva for the WHO in 1967, at 38, he wasn’t thrilled. But if they wanted the world rid of the virus in ten years, he would give it his best shot.

Not by himself, of course. “Target Zero” came to involve almost everyone in the affected countries, from scientists in labs to government ministers to local health officers and elders who could neither read nor write. His modus operandi, “surveillance-containment”, required not mass vaccination but pinning down each case and vaccinating all contacts; it needed the co-operation even of villagers and schoolchildren, who learned to spot the tell-tale rash of Variola major, like buckshot embedded in the skin. His own staff was tiny; but some 200,000 locally recruited people also worked for him, in 50 countries.

This crowd of helpers, which delighted him, meant that no Nobel prize could be given for wiping out smallpox. If it had been, he might have shared it with William Foege, who first devised surveillance-containment, and Benjamin Rubin, inventor of the bifurcated needle, an easy and ingenious instrument which used a mere 25% of the normal amount of vaccine. But he was the man who kept the whole show on the road, strongarming governments to provide funds and to make their own vaccines of the necessary purity, potency and stability; conducting his own cold-war diplomacy with the notably helpful Russians; muscling past the tentacular regional bureaucracies of the WHO; sending out continual reports on progress; and answering within three days, before e-mail, every plea that came in from the field.

Problems rose up constantly. In Ethiopia, rebels attacked the vaccinators. Afghanistan brought deep snow and no maps. In Bangladesh trucks could not cross the bamboo bridges; in India mourners had to be stopped from floating smallpox corpses down the Ganges. He experienced most of this himself, frequently decamping from cramped Geneva armed with “Scottish wine” (his favourite medicine) to urge on the troops. Out in the trenches he also faced the full horror of what he was fighting. At a hospital in Dhaka the stench of leaking pus, the pustule-covered hands stretched towards him, the flies clustering on dying eyes, convinced him anew that he had to win this war.

Overall—and only he had the full picture—the effort ebbed and flowed. Good progress in a country might be suddenly reversed by war, as in Biafra, Ethiopia and Bangladesh, by flows of infected refugees or, in Somalia, by nomads wandering across a border. Heartening figures might turn out to be colossal under-reporting. By 1975, however, almost all of Asia and Africa was free of smallpox. The last naturally occurring case, a Somali cook, was recorded in 1977. There followed two anxious years of more surveillance, when Dr Henderson was not quite sure they had really done it. By December 1979 he knew they had.

The lurking menace

Yet this was not the end of his worries about smallpox. Some still survived in the world, in various laboratories, which might be weaponised and used against a population which, increasingly, would have no herd immunity. From his new positions, as professor of epidemiology at Johns Hopkins and an adviser to presidents, he called for the virus to be destroyed and, at the same time, for vaccine to be stockpiled again. In 2001 he masterminded a simulation, “Dark Winter”, in which a smallpox epidemic hit the Midwest and America’s health system failed.

“Future generations”, wrote Thomas Jefferson to Edward Jenner, the inventor of the smallpox vaccine, “will know by history only that the loathsome smallpox has existed.” Two hundred years later Dr Henderson was almost able to have that confidence. But not quite.

Reuters As soon as a disease broke out anywhere in the world, Henderson (left) would dash to tackle it—becoming a proper “shoeleather” epidemiologist, as opposed to a “shiny-pants” desk-bound sort.