A shift in the burden

Evidence that the AIDS virus passed from chimpanzees to humans through polio vaccine has grown, says a well-known science writer

Matt Ridley

Daily Telegraph (UK), 15 September 2000, p. A15

LONDON - In these days of managed news, this week's British Royal Society conference on the origin of AIDS had unusual frissons of unpredictability. At stake is the hypothesis that the disease arose from polio vaccines tested in central Africa in the late 1950s.

Those vaccines may have been made with tissue from chimpanzee kidneys and may have been contaminated with the chimpanzee precursor of the AIDS virus.

The meeting heard new evidence of yet another chimpanzee facility in central Africa intimately linked with vaccine creation and polio inoculation. In the audience was the very scientist who knows exactly what happened: Hilary Koprowski.

I am an unashamed fan of progress. I think innovation and technology have prevented more premature deaths and alleviated more environmental disasters than they have caused. I detest the hypocrisy of those who protest against free trade while using mobile telephones and of those who would deny genetically modified crops to poor countries from the comfort of organic luxury.

Vaccination is probably the simplest and best example of how science has made the present a better place than the past, not least in all but eradicating polio. Its benefit-cost ratio is enormous.

So it is all the more uncomfortable for me to admit that, in the case of this controversy, the evidence for an abuse of science -- mostly unwitting -- is strong enough to shift the burden of proof on to those who would deny it.

Edward Hooper, author of The River, a book that documents his nearly 10 years of research into those events, arrived at the conference fresh from Burundi and Rwanda. In Burundi he found a laboratory where chimpanzees were kept in the mid-1950s.

As he had done in the Congo in 1999, so in Burundi, Hooper talked to a microscopist, who described frequent operations to remove single kidneys from the chimps; the kidneys then being shipped to a vaccine-making institute in Astrida (now Butare) in Rwanda.

In this exact area, in 1957 and 1958, there was a large trial of the new "Chat" oral polio vaccine, which Koprowski had invented by growing polio viruses on primate kidneys, of unspecified species. In this exact area, 20 years later, the first widespread rural infection with HIV in the world came to light.

Hooper also related his conversations with Louis Bugyaki, a Belgian veterinary scientist who was present in Stanleyville (now Kisangani) at the time. He said that, in his opinion, the chimpanzee kidneys were harvested for growing polio viruses to make vaccines.

No other convincing account of their use has been given.

It was known to be possible to grow the virus on chimp kidneys. And Koprowski, whose whole ambition was taken up with the entirely noble search for an effective polio vaccine, not only assembled about 400 wild-caught chimps at a facility near Stanleyville for some purpose, but also ordered huge tests of vaccines mostly in Belgium's African colonies. Why?

The coincidence between the first cases of HIV infection and the polio vaccination trials, both in time (1959) and place (Leopoldville, Burundi and some other parts of the Congo) is suggestive, but not conclusive.

That vaccines can be contaminated with primate viruses is certain -- it happened about the same time with SV40, a cancer-causing virus from rhesus monkeys that contaminated polio vaccines. That an oral vaccine could infect people is also certain.

HIV infection via the mouth is well-established, especially among infants infected through breast milk. So there is nothing implausible about the theory.

Its detractors have put forward four counter-arguments. The first was a case of a sailor from Manchester, who might have died of AIDS before the vaccine trials. That is now exploded: His tissues prove he did not have HIV. The second is a set of samples of the relevant vaccine batch from a freezer in Philadelphia, which prove to be HIV-free and made not from chimps. But Hooper has now shown that at least some of the vaccine batches were made in Africa, not in the United States.

The third counter-argument is that the genes of the modern strains of HIV suggest a family tree going back at least to 1940 and probably to 1930. This is irrelevant if more than one infected chimp was used as a kidney donor: the common viral ancestor might have been in a chimp, not a human. Given the scale of the vaccine trials, it is likely that, if contamination occurred at all, it was probably of more than one strain.

The fourth counter-argument is socio-economic: that urbanization, sexual freedom and migration in Congo during the 1950s were sufficient to reawaken any small-scale infection caused by "natural transfer" from a chimp to a hunter and turn it into a pandemic.

This argument wholly fails to explain why the slave trade and the Belgian mining industries, which were just as socially disruptive, failed to do the same. The conference also heard how rare the virus is among the very people who should be most exposed if it comes from ape-hunting: the pygmies.

Koprowski and his collaborators (mainly Belgian) were engaged in a race against the rival Sabin and Salk polio vaccines, and they were, in the course of research, killing chimpanzees, which were already a partly protected species even in Belgian colonies. This may account for the secrecy.

Yet if they were doing this to grow human polio vaccines, it would not only have been a technically sensible strategy -- chimp kidneys would have been ideal for the job -- but also a legal and, as far as they knew, a safe one. At the time, nobody knew about the problem of contaminant viruses from primates.

If Hooper is wrong, he may have already harmed the campaign to eradicate polio from the world -- one of the great triumphs of Western medicine. If he is right, Western medicine will face the wrath of an entire continent ravaged by the worst pandemic since the Black Death.

This document is located amongst material concerning the Royal Society meeting, in the section on polio vaccines and the origin of AIDS on Brian Martin's website on suppression of dissent.