Copyright 1999 Times Newspapers Limited
The Times (London)
The origin of Aids remains a mystery. A new book claims that its roots may lie in a polio vaccine given to Africans in the 1950s, says Jessica Davies
A vial of vaccine locked in freezer number 178 and located in room 369 of the Wistar Institute, a biomedical research establishment in Philadelphia, may contain the answer to one of medicine’s greatest enigmas: how Aids, one of the most lethal and infectious medical conditions that the world has known, was first unleashed on mankind.
It is now 18 years since news of a mysterious illness affecting the gay community in Los Angeles began to catch public attention, and since then Aids-related diseases have ravaged lives across the globe, infecting one per cent of humanity. A terrifying, apparently unstoppable pandemic, it has killed more than 15 million people, a figure that will rise to 16 million by the new millennium. In its most dreadful, African manifestation, HIV currently ticks like a time bomb in the blood of 23 million men, women and children, most of whom will die from Aids-related conditions.
Worse than the Black Death, or any war or famine visited upon Africa, and soon to exceed the Spanish flu epidemic of 1918 in terms of deaths, Aids can no longer be dismissed as an esoteric Western gay/intravenous drug users’ “problem”. For its real threat is as a rampant, indiscriminate Third World killer.
In South Africa 20 per cent of the workforce will die in the next five years. In Zimbabwe a million children have lost their mothers. Aids in Rwanda and eight other African countries has brought life expectancy down from 60 to 43. The agony and the grief are impossible to imagine. Yet still there is no vaccine. Nor, crucially, do we understand the genesis of the tragedy – a genesis which, some argue, might point the way to a cure.
What we do know is that the human immunodeficiency virus, HIV, probably originated in central Africa, and that its closest ancestors are simian immunodeficiency viruses (SIVs) found in African primates. How, and when, African primates infected human beings are essentially the two critical questions that have remained unanswered.
Most widely accepted is the “natural transfer” theory: the practice of hunting and preparing monkeys for the pot may have allowed SIVs to jump the species barrier “naturally”, with devastating consequences. However, as Africans have hunted and eaten monkeys and apes since time began, this hypothesis leaves open the question of why the earliest outbreaks of Aids did not occur until the second half of the 20th century.
Edward Hooper, who as a journalist based in Africa during the mid-1980s filed the earliest reports for the BBC of the unfolding African tragedy, subsequently wrote a book (Slim) about the East African Aids epidemic. He was one of a handful of informed observers who felt that somewhere there lay clues that would lead back to the possible source of Aids.
Having witnessed African friends scythed down by the disease and having understood long before most the scale of this human tragedy, he admits that he was also driven by personal motives. “1 had been promiscuous for much of my time in Africa. I hadn’t used condoms and I wasn’t HIV positive so I considered myself very lucky.” In l990 he set out to track down those elusive clues.
The River, a great doorstep of a book that is the result of his labours – nine years of research comprising 600 interviews – posits in meticulous detail a theory that has put the medical establishment on the defensive.
It is that Aids was unwittingly introduced by doctors administering contaminated oral polio vaccines (OPVs) to hundreds of thousands of Africans in the 1950s. In other words, that medical intervention designed to stop the most feared disease of the postwar era accidentally conjured up a terrible new disease that is responsible for more deaths than the combined efforts of Hitler, Stalin and Pol Pot. That it was not Africans who gave Aids to the West, but Western medicine at the end of the colonial era that gave it to them.
Hooper’s trail of evidence, which leads to that Wistar Institute freezer, adds flesh to the bones of a thesis – known as the OPV-Aids theory – that others have argued before but never in such detail. The hypothesis centres on the possible contamination by a monkey virus of an experimental vaccine known as CHAT.
Developed in the 1950s at the Wistar by a Polish emigre, Dr Hilary Koprowski, it was administered between 1957 and 1960 in mass trials to more than a million Africans in the then Belgian colonies of the Congo and Ruanda-Urundi (now Rwanda and Burundi).
To this day polio vaccines are cultivated in monkey kidney tissue, and in common with his rivals in the race to develop an effective cure for polio, Koprowski found this medium – technically known as a substrate – ideal for growing polio viruses to use in his CHAT vaccine. Albert Sabin, whose vaccine was eventually chosen over Koprowski’s for worldwide licensing, was known to have favoured the kidneys of an Asian monkey species. However, Koprowski did not reveal the source of his vaccine substrate in the numerous articles he wrote at the time.
Nor did he clear the air in 1992 when the OPV-Aids theory, implicating his vaccine, was first outlined in an article in Rolling Stone magazine. Indeed, according to Hooper, he gave four apparently conflicting accounts and went on to say that any records he once possessed had been lost in a move. Oddly, official records of the vaccination programme that ought to reside in the Belgian foreign ministry archives are also missing. More recently, Dr Koprowski has said that he used only kidneys from a species called the rhesus macaque – which is not naturally infected with SIV.
This last claim is important because Hooper believes that if there were contamination of the Koprowski vaccine by SIV, it occurred at the cultivation stage. Could it be, Hooper suggests, that SIV-contaminated primate kidneys were used for cultivating CHAT? And could it be that Koprowski’s vaccine substrate was in fact chimpanzee kidneys?
The significance of this is that HIV-1, the virus responsible for most Aids fatalities, is genetically most closely related to the SIV found in chimpanzees living in the part of Africa where Koprowski carried out his trials. Is it not possible that a batch of vaccine was literally poisoned by the kidneys of an infected chimpanzee, and that the SIV was thus passed on to thousands of innocent people?
Without records, proof either way is elusive. Hooper himself concedes that his findings are not conclusive. Yet it is perhaps puzzling that all but one of those who worked on CHAT and were still alive to be interviewed by Hooper could not remember the source of the vaccine substrate. The exception was Gaston Ninane, a Belgian virologist on the team, who told Hooper that chimp kidney tissue culture had been used – but then retracted the statement a few minutes later.
What is known for certain is that Dr Koprowski did indeed use some 400 chimps, held at a camp at Lindi in the Belgian Congo, to test the safety and efficacy of his vaccine. It is known that about 100 of the animals were used for these tests. What is not clear is the fate of the remaining chimps. Again, there are no records.
Since the dangers of SIVs were only discovered much later, Dr Koprowski could not have known that the chimpanzees had the potential to pass on a lethal virus, and it seems reasonable to conjecture that these animals would also have been an obvious source of kidney tissue for cultivating CHAT, not least because chimpanzee kidneys were known to be a very efficient medium for growing the polio virus. Why use another type of monkey when you have 400 chimps sitting in cages?
Dr Koprowski has strenuously denied using chimpanzee kidneys to cultivate CHAT, but Hooper has evidence that chimp kidneys were flown out of Africa to the Wistar Institute, of which Dr Koprowski was director, where batches of CHAT were prepared. He also points out that statistically between eight and 12 of the Lindi chimps would have been naturally infected with SIV, and that further spread could have occurred in the camp.
Perhaps more intriguing is the startling evidence that emerges by comparing a map of the 1957-1960 African CHAT trials with a map showing the first instances of HIV infection and Aids in Africa. Of the 38 confirmed or probable cases recorded before 1980, 31 come from the Congo, Rwanda and Burundi. And of the 39 African HlV-positive blood samples taken during that period, more than 87 per cent come from towns where CHAT trials took place, and 100 per cent fall within a 90-mile radius of CHAT vaccination sites.
As Hooper says: “The synchronicity of time and place is remarkable.” He points out moreover that the earliest known sample of HIV-positive blood was taken in 1959 from a man who lived in Leopoldville (now Kinshasa), a CHAT vaccination site, and that nobody has been able to find a sample from before that date or, more to the point, from before the time of the first CHAT feedings.
The evolutionary biologist Bill Hamilton, a Royal Society research professor at Oxford and author of the foreword for Hooper’s book, believes that these remarkable correlations ought to be taken seriously. “None of the facts amounts to proof,” he agrees, “but taken together the trend and accumulation is impressive. At least the OPV theory of the origin of Aids now merits our acute attention.”
Indeed, when asked how likely it is that the OPV-Aids theory is right, he puts the probability at 95 per cent. “I cannot see how this stream of coincidences can merely be coincidences. What is the chance of all these early cases occurring in the specific places where CHAT was fed?”
He proposes the parallel scenario of a new form of cancer occurring among the families of people employed in a new chemical industry in this country and asks: “Would we not suspect a causal link, or would we dismiss as groundless the fears of those who suggested such a link?”
In the context of the reaction to the OPV-Aids theory, this is no idle question. For, as Hooper discovered, scientists and doctors have been quick to reject the hypothesis. The Wistar Institute, which set up a committee to investigate the claims when they were firstmade by Rolling Stone in 1992, concluded that the theory was highly unlikely. Dr Koprowski, meanwhile, has stopped giving interviews on the subject and now refers all inquiries to his lawyers.
More worryingly, some might say, the wider medical and scientific community has remained hostile. Throughout his pursuit of the source of Aids, Hooper has met with what Professor Hamilton describes as “a wall of silence”. Until recently, respected journals would not publish his ideas; the medical fraternity seemed disinclined to take him seriously. Fairly typical was a recent review of The River in Nature magazine by John P. Moore, a microbiologist specialising in Aids research, which dismissed the hypothesis as a conspiracy theory on a par with the mad speculations about who really killed John F. Kennedy. Healthy scepticism is one thing; outright dismissal of plausible evidence is quite another. “Frankly, I believe the concept of a disease as huge as this caused by medical intervention is threatening to the basic tenets of science,” says Hooper.
“The medical establishment cannot bring itself to believe that a disaster of this magnitude could have been started by one of its own,” Professor Hamilton says. “Perhaps if I had been through a rigorous medical training, I would be more hostile than I am. My experience has been that nobody wants to talk about this and there is always a lot of nervous sidestepping whenever I mention it.
“Only recently a colleague said that he supposed there might be truth in the theory but that he wasn’t going to be publishing anything on it. He went on to say that he would lose his grant from the medical research body that supports him.
One oft-repeated argument is that there is surely no benefit in raking over the past when energies would be better directed in making life more comfortable for the victims of Aids. But that is to ignore the real possibility that the past holds the key to an Aids-free future.
The distinguished immunologist Omar Bagasra, who supports the OPV-Aids theory, suggests in a new book – HIV and Molecular Immunology: Prospects for an Aids Vaccine – that a cure may already lie with those same people who were vaccinated with CHAT all those years ago in the Belgian Congo. Put simply, if the theory is correct, vaccinees would have been infected to varying degrees. Pathogenic (disease-causing) strains of SIV would have been passed on as Aids; non-pathogenic strains would have provided immunisation against the condition. Thus, survivors of the Congo CHAT trials might carry “the sort of viral particles that we can utilise for future Aids vaccines”.
Professor Hamilton sees other important lessons for medical science which we ignore at our peril – not least in the new field of xenotransplants where the temptations of huge profit may blind medicine to the inherent dangers of implanting bits of other species, along with as yet undetected viruses, into the human body. He explains that this may have the added danger that recipients’ immune systems are routinely repressed to prevent rejection of the new organ – a process that featherbeds the first steps that a new virus might take on entering the human species.
In common with other supporters of the OPV-Aids theory, he would like the Wistar Institute to fulfil the promise it made some years ago to release for independent testing a sample of CHAT that was part of a production lot used in Leopoldville in the late 1950s. It is this sample which resides in that freezer in room 369.
In response to inquiries about the sample by Edward Hooper, Giovanni Rovera, Dr Koprowski’s successor as director of the Wistar, wrote a letter explaining: “In consultation with my colleagues, I decided not to proceed in this matter since the results of any test on such a small sample of virus stock, no matter how competently performed, would not have been accepted in the scientific community as conclusive.” Hooper maintains, however, that the amount – 5 millilitres – would be enough for several laboratories to carry out detailed DNA sequencing tests. Even if this particular sample proved to be free of contamination, the tests could clear up the mystery of whether the vaccine was cultivated in chimpanzee kidneys. That in itself might force out of medical science the fair hearing that Hooper’s evidence deserves. Another useful test would be on stored blood samples in Africa, dating from before the trials. If HIV were found, the theory would be demolished.
The Wistar’s apparent reluctance over the release of the CHAT sample has angered Aids activists in the US, who are talking of demonstrations and calling for the institute’s funding to be frozen until the issue is settled. So far the medical establishment has largely regarded these arguments as little more than an irritating sideshow. Why should it want to re-examine what may turn out to be its most disastrous experiment when so much work remains to be done on the development of a vaccine that might halt the tragedy? A number of trials are being mooted.
There are those who are already sounding warnings about the dangers of releasing a new genie out of the bottle, and Bagasra has written that Aids vaccine trials may give rise to even deadlier strains of the HIV virus. History may yet repeat itself: it has already been suggested that those trials, when they happen, will take place in Africa.
The River by Edward Hooper, Allen Lane The Penguin Press, Pounds 25.