Why the Worobey/Hahn "refutation" of OPV/AIDS theory is wrong, and a warning about dishonest tactics used by opponents of the theory

Edward Hooper


This item is part of a collection of material on

Polio vaccines and the origin of AIDS

which in turn is part of Brian Martin's website on suppression of dissent.

The latest alleged refutation of the OPV theory is not a refutation at all, not least because it is based around a false premise.

It features in a "brief communication" in Nature magazine by Michael Worobey, Beatrice Hahn and others, entitled: "Contaminated polio vaccine theory refuted". [Nature; 2004; Vol. 428; p. 820.] The title alone reveals that the intention of the article is not to provide new and relevant information about the early history of HIV-1, but to attempt to refute a theory that medical scientists find uncomfortable - namely that members of their own profession may unwittingly have started the AIDS pandemic.

Nature has a long history of bias against this theory. Worobey’s article was given substantial advance publicity on Nature’s web-site, and it is apparently no coincidence that it was published the day before the broadcast of a revelatory 90-minute documentary, "The Origins of AIDS", on the French government channel, France2.

This pre-emptive publicity was to an extent successful, because it distracted many members of the French press from the evidence presented in the MFP/Galafilm documentary.

In a nutshell, this is that in the late 1950s, scientists working at the medical laboratory of Stanleyville [Kisangani], and at the nearby chimpanzee camp at Lindi, prepared a unique version of CHAT (an experimental oral polio vaccine, OPV) in the cells and sera of chimpanzees, the species that is host to the direct ancestor to HIV-1. This vaccine was later fed to approximately a million persons in the DRC, Burundi and Rwanda, in the same towns and villages which later saw the first emergence of HIV-1 and AIDS.

Why the "refutation" is false

There are three main reasons why the alleged refutation by Worobey and Hahn is false:

(a) chimps used in the OPV experiments came from an area of 300,000 square miles, and not just from "the vicinity of Stanleyville";

(b) some of the chimps used in the OPV experiments came from an area where Pan troglodytes troglodytes (the chimp subspecies which Hahn and Worobey claim to be the only host to the ancestor of HIV-1) are found;

(c) it is likely that HIV-1 arose through recombination between different chimp SIVs.


a) The geographical source of the chimps used in the OPV work.

The first paragraph of Worobey’s article states that: "The ‘OPV/AIDS theory’ claims that chimpanzees from the vicinity of Stanleyville - now Kisangani in the Democratic Republic of Congo [DRC] - were the source of a simian immunodeficiency virus (SIVcpz) that was transmitted to humans when chimpanzee tissues were allegedly used in the preparation of OPV."

The second part of this statement is true. The first part of the statement is not true and is, I believe, deliberately misleading.

The 600-odd chimpanzees that were held at Lindi camp, and which were used in the OPV experiments, were not just collected from around Stanleyville/Kisangani, but from an area of over 300,000 square miles of rain forest covering much of northern DRC, extending almost to Uganda in the east, and to the borders of Central African Republic and Sudan in the north. Nobody has yet reported any results of SIV testing of chimps from those regions.

The latest Worobey/Hahn claims actually centre on the observation that an SIV sequence obtained from "the vicinity of Kisangani" (actually from the Parisi forest, 130 kilometres to the south-east - an area which is not known to have provided chimps for the OPV work), clusters with other sequences of SIV from the Pan troglodytes schweinfurthii (Pts) subspecies that is found in the DRC.

Hahn and Worobey contend that Pts SIVs are not as closely related to the human pandemic virus, HIV-1, as the SIVs from Pan troglodytes troglodytes (Ptt) chimps, found in Cameroon, Gabon and Congo Brazzaville.

On the basis of the relatively little sampling that has been done, this statement is true. However, the hypothesis is far from proven. Many geneticists feel it is far too early to make such sweeping claims, when no chimp SIV sequences from (for instance) northern DRC, or Congo Brazzaville, have yet been reported.

It may well be that some Pts SIV sequences are as close to HIV-1 as the Ptt SIV sequences. Or indeed, even closer.

b) The probability that Ptt chimps were also present at Lindi.

But even if we assume that the Hahn/Worobey hypothesis is right, and that the SIV of Ptt chimps is the only true ancestor of HIV-1, this still does not refute the OPV theory. This is because testimonial and documentary evidence indicates a high probability that at least some of the chimps held at Lindi camp were Pan troglodytes troglodytes.

Several sources (including the late Gilbert Rollais, who coordinated the Lindi captures) have confirmed that some of the 600-odd Lindi chimps were bought locally from Africans.

In the last two months I have interviewed (a) a journalist who worked in Stanleyville throughout the fifties and who visited Lindi camp on several occasions, and (b) the Swiss chimpanzee expert Karl Ammann, who twice travelled up and down the Congo river on ferries in the 1980s. Both men testified that they had frequently witnessed chimps being brought up-river by ferry for sale in Stanleyville/Kisangani, and that some may well have been Ptt. Ammann e-mailed me that: "On each occasion there were chimps that came on [to the ferry] around Mbandaka and Bumba, and there is no reason why chimps would not come on board from the other side of the river, the other Congo, which of course would be Ptt." [A large part of Mbandaka territoire, formerly Coquilhatville, faces Congo Brazzaville, which is part of the Ptt range, across the Congo river.]

There are records available for only a small subset of 54 (less than 10%) of the Lindi chimps, which indicate that two animals came from Stanleyville zoo (original source unknown), and one from Coquilhatville territoire. This latter animal (No. 98) survived at Lindi camp for the unusually long period of at least two years (from April 1957 to April 1959). No. 98 was not a pygmy chimp or bonobo (Pan paniscus), the only other species held at Lindi, because it is well-documented that all the bonobos had been "used up" in experiments before 1959. Clearly, therefore, chimp #98 could have been a Pan troglodytes troglodytes, rather than a Pan troglodytes schweinfurthii.

The genetic differences between Ptt and Pts are minimal (and there is a growing argument that they should be classified as a single species). A key point is that without knowing the precise source, nobody would be able to distinguish reliably between troglodytes and schweinfurthii once the chimp had arrived at Lindi.

When I told Robin Weiss, a leading opponent of the OPV theory, about the Coquilhatville chimp at a lunch attended by a dozen scientists (after the Lincei conference on "Origin of HIV and Emerging Persistent Viruses" in September 2001), he conceded that the presence of a single troglodytes chimp at Lindi would "dispose of" this argument against the OPV theory.

Professor Weiss may be biased in what he has written about the origins of AIDS in the last four years, but he knows that chimps at Lindi were routinely co-caged and group-caged, meaning that if even a single SIV-infected troglodytes was present at the camp, then this virus (Hahn’s designated ancestral AIDS virus) could have spread extensively between animals, and that different viral variants could have ended up in the OPV that was prepared from their tissues and serum.

Yet now we have Nature (a magazine over which Robin Weiss exerts enormous influence in terms of AIDS coverage) claiming that this same old Ptt/Pts argument "refutes" the theory.

c) The role of recombination.

However, the OPV/AIDS theory is not dependent on an SIV-infected Ptt chimp (or chimps) being present at Lindi camp.

Although it is now generally accepted that the HIV-1 ancestor must have been a chimpanzee SIV, there are substantial variations in the SIV sequences found in different chimp troupes.

The chimp SIVs from Cameroon and Gabon favoured by Hahn and Worobey as the ancestral source of pandemic HIV-1 actually have only about 80% homology with HIV-1. (By contrast, the sooty mangabey SIV that is the parent of HIV-2 is almost identical to some variants of the human virus.)

One possible explanation for the rather large 20% genetic "gap" between Ptt SIV and HIV-1 may be simply that the specific group of chimps bearing the ancestral virus (whether Ptt or Pts) has not yet been sampled.

But another possible explanation is that HIV-1 evolved as a result of recombination between two different chimp SIVs (whether Ptt or Pts). Clearly this could have happened during the co-caging or group caging at Lindi camp. Alternatively, it could have happened when two different chimp SIVs recombined in one of the tissue cultures (containing chimp cells and chimp sera) that were used to grow CHAT vaccine at the Laboratoire Medicale de Stanleyville.

If such recombination occurred at an early stage of the evolution of HIV-1, it would not be detectable by phylogenetic analysis.

Biased reporting

The foregoing indicates that this latest "refutation" of the OPV/AIDS theory is innately flawed.

This is only the latest in a long line of unscientific claims about the origins of AIDS that have appeared in the pages of those august journals Nature and Science, and is no more convincing that its predecessors.

Neither journal has ever published any article supporting, or expounding, the OPV/AIDS theory. Yet since 1992 they have published a series of flawed refutations, including a set of co-ordinated articles and commentaries in April 2001 which variously asserted that the OPV theory had been "destroyed", and had "died its final death". Three years later, it is apparent that those claims were not just premature, but erroneous.

In private and in "unattributable" conversations, two of the leading OPV sceptics have admitted that the OPV/AIDS theory is plausible and possible, but that they will never state this publicly unless there is incontrovertible evidence to support it. What these men actually do in public, however, is rather different, and deeply cynical. They assert that the theory has been refuted, even when they know that this is not so.

The worry about this (and about the many other misrepresentation and, indeed, lies that have been reported and told by those who are most actively opposed to the OPV theory) is that the dishonest science might carry over into other areas.

Concern about possible faking of an ancient HIV-1 sample

Of particular concern is the recent confirmation that ancient autopsy samples (slides and paraffin blocks from the years 1955-1958) from the basement of the old medical laboratory in Stanleyville (where the OPV experiments were based), were obtained about a year ago by a team of senior Belgian and American scientists led by Dr Stanley Plotkin.

In the late fifties, Plotkin was principal assistant to Dr Hilary Koprowski on the development and testing of CHAT vaccine, including the experimental programme in the Belgian Congo/DRC.

More recently, his support team of scientists has been active in persuading some of those witnesses who had earlier given significant testimony to me to either retract or modify their statements. In several instances, I have evidence of inappropriate pressures being placed on witnesses by members of Plotkin’s team, including attempts to badger a witness into signing a pre-typed statement that was untrue in several respects.

It is known that the Plotkin group has put considerable time, effort and money into obtaining the 1950s Stanleyville samples. Indeed, on one occasion in 2001, an unsuccessful attempt was made by a Belgian collaborator to misappropriate several hundred of the slides.

The news that they have been successful is worrying, because in no respect can the Plotkin group be considered "independent testers" of these important biomedical materials.

The Plotkins have kept their acquisition of these samples a secret. I only came to learn that they had acquired them because I recently met a Belgian professor who had played some role in helping the Plotkins in their early research. He expressed surprise and some concern that they had reported nothing of their findings.

It is believed that some of these samples (from after the start of the OPV trials) may well contain genuine evidence of early HIV-1.

The concern here is not just that an early HIV-positive sample from this era might end up unreported.

It is that an HIV-positive sample from Stanleyville in 1957 might somehow end up misfiled with another group of samples from, say, Brazzaville in 1951, ie from before the time of the OPV trials.

If such a sample were subsequently to be tested in good faith by an independent researcher, then it might subsequently be proclaimed as yet another "disproof" (indeed, as "a final and incontrovertible disproof") of the OPV/AIDS theory.

Edward Hooper. May 1st, 2004