Hooper recently interviewed several of those who used to work in the Medical Laboratory of Stanleyville, Belgian Congo, and at the nearby Lindi chimpanzee camp, in the late 1950s.

Their testimonies reveal that CHAT polio vaccine was being prepared locally at the medical laboratory -- at a time when the only tissue culture available in that lab was made from chimpanzee kidney cells.

This is significant, because the common chimpanzee is the carrier of a virus (SIVcpz) which is the immediate ancestor of HIV-1, the virus responsible for the AIDS pandemic. To date, HIV-1 has infected more than 60 million, and caused 22 million AIDS deaths world-wide.

Furthermore, there are remarkable correlations between the towns and villages where CHAT vaccine was fed in the late fifties, and the first appearances of HIV-1 and AIDS in Africa.

This does not prove that CHAT started AIDS. But at this point many will consider that the OPV theory has become the most plausible theory of origin. This new evidence also raises questions about the ways in which the scientific community has, until now, responded to an "uncomfortable theory".

In September 1999, Edward Hooper's book The River was published. It was greeted with critical acclaim by many reviewers, but with outrage and defensiveness from a large part of the scientific community.

Controversially, the book proposed that the AIDS pandemic might have been caused iatrogenically -- through medical intervention.

It pointed specifically to the trials of an experimental oral polio vaccine (OPV) called CHAT in central Africa in the late fifties. CHAT had been developed by Dr Hilary Koprowski of the Wistar Institute in Philadelphia. Hooper found that 68% of the cities, towns and villages where AIDS first emerged in Africa (and therefore the world) had been vaccinated with CHAT. So had 85% of the places where HIV-1 first emerged in Africa.

He proposed that CHAT vaccine might have been made in cells from the common chimpanzee, which carry a simian immunodeficiency virus (SIV) that is the closest relative to HIV-1. But there was no proof.

A meeting on "The Origins of HIV and the AIDS Epidemic", co-organised by a leading AIDS virologist, Professor Robin Weiss, was held at the Royal Society in London in September 2000, and the results of tests on samples of CHAT released by the Wistar Institute were announced. The samples were found to contain no HIV, SIV, or chimpanzee DNA.

When brief follow-up papers about the testing were published earlier this year, the scientific press concluded that the theory had been comprehensively disproved. "Disputed AIDS theory dies its final death", ran the headline in Science. "Polio vaccines exonerated", was the title of Robin Weissās commentary in Nature, which ended with a memorable sound-bite.

"Some beautiful facts", wrote Weiss, "have destroyed an ugly theory". It was an irresponsible claim, for no relevant facts (beautiful or otherwise) had been presented.

It was also incorrect, for further investigations in Kisangani (formerly Stanleyville) in the Democratic Republic of the Congo (ex-Belgian Congo), where Koprowski and his Belgian colleagues operated a huge chimpanzee colony at the end of the fifties, have revealed some startling information.

Approximately 600 chimps were held at Lindi camp in the three years of its existence, and nearly all were sacrificed, with their organs and blood being removed in canisters.

The man who carried out most of these operations, Dr Paul Osterrieth, was head of virology at the nearby Medical Laboratory of Stanleyville. One of Dr Osterrieth's assistants from this era has revealed that between 1958 and 1960, Osterrieth was preparing oral polio vaccine in his lab. Apparently he made a fresh batch every time a new order came in from the provincial director of medicine.

Furthermore, he was apparently making these polio vaccine batches in a tissue culture of chimpanzee cells. Osterreith's own statements, combined with documents from the era, reveal that this was the only available culture in the virology lab at that time.

Dr Osterrieth's assistant has given an account of helping to administer this same vaccine, by mouth, to over 3,000 people at Stanleyville military camp on February 27, 1958. (This was "Koprowski Day", the eighth anniversary of Koprowski's first feeding of OPV to a human being.) Altogether, between 1957 and 1960, there were 27 CHAT vaccination campaigns in the Congo, Rwanda and Burundi. At present, there is no way of knowing which of the other campaigns involved CHAT vaccine made in chimp cells.

However, five of the sixteen places where HIV-1 is known to have been present in Africa up to and including 1981 were places where CHAT vaccine was given between February and April 1958. These are the months for which there is evidence that the chimpanzee cell cultures was being prepared in Osterrieth's laboratory. Three of these five places are small towns and villages of less than 5,000 people -- not the sort of places one would expect to become infected so early in the epidemic. Unless, of course, the polio vaccine was involved.

The Lindi chimps were routinely caged together, which means that SIV was in all probability present and spreading at the camp. Thus the batches of CHAT vaccine prepared by Osterrieth were also likely to have been unwittingly contaminated with chimp SIV. This is made all the more likely by the fact that the chimpanzee tissue cultures did not employ trypsin, a chemical reagent which largely inactivates SIV.

Both Dr Osterrieth and Dr Koprowski have consistently denied that any CHAT vaccine was ever prepared in chimpanzee cells. But now, for the first time, there is evidence that contradicts these claims.

This does not prove that CHAT vaccine started the AIDS epidemic. But there are flaws and shortcomings in every one of the scientific arguments which have been used to counter the OPV theory -- including the much-vaunted phylogenetic argument, which dates the AIDS epidemic to 1931.

A growing number of geneticists suspect that phylogenetic analysis is not an appropriate method for dating the age of HIV-1, and that specific dates like 1931 represent little more than "educated guesses".

Hooper concludes: "I believe that this new information about CHAT preparation in the Belgian Congo in the 1950s is vitally important, and not only with regard to the OPV theory, and the question of how AIDS may have started. It also raises important ethical questions about the ways in which modern research is funded; the ways in which the scientific establishment responds to theories which it finds threatening, or embarrassing; and the ways in which experimental trials have been, and are still being, conducted in the developing world."

On Friday September 28th, Edward Hooper will be presenting his latest findings at the conference on the "Origin of HIV and Emerging Persistent Viruses", at the Accademia Nazionale dei Lincei (the oldest scientific institute in the world), in Rome (telephone: +39 06 6861159/ 6868223). Also speaking will be several geneticists, including Paul Sharp and Mikkel Schierup.

A copy of Hooper's speech for Lincei, "The origin of HIV-1 Group M: the CHAT polio vaccine theory", follows.

Bill Hamilton probably had the highest standards of probity of anyone I have ever known. He was (as is widely recognised) softly-spoken, modest and generous to a fault. But there was also another side to Bill -- less familiar save to those who were close to him. He could be assertive (sometimes explosively so) when he felt that a wrong was being done, or that an untruth was being presented as a truth. I am confident, therefore, that Bill would not disapprove of the robust speech that I am going to make today.

In August 1999, after nine years of research and writing, my book The River was published.[i] In it, I examined more than fifteen hypotheses about how the AIDS pandemic might have begun.[ii] I proposed that the field could actually be narrowed down to two competing theories -- one involving a "natural" zoonosis, and the other involving an iatrogenic (or physician-caused) event. Both theories sought to explain how humans had become infected with the simian immunodeficiency virus (SIV) of the common chimpanzee (Pan troglodytes), which for some years has been recognised as the closest ancestor to the major HIV-1 variant, Group M.[iii]

I christened the more widely accepted theory of origin the "natural transfer" or "cut hunter" theory. As espoused by its leading proponents,[iv] this theory proposes that someone who hunted, skinned, ate or played with a chimpanzee, became infected with chimp SIV in or around the 1930s, somewhere in the west central African region of Congo Brazzaville, Gabon or Cameroon. [Chimp distribution map.] It further proposes that the initial infectee, or someone infected by them, ended up not long afterwards in Leopoldville, (now Kinshasa, the capital of the DRC, the Democratic Republic of Congo). There, the theory goes, transmission to other parties began, and the new human virus then began to spread upriver to infect people in other parts of the DRC and, by the end of the seventies, in other parts of Africa.[v]

The most plausible iatrogenic theory of origin, and the one which I came to favour, is called the oral polio vaccine (OPV) hypothesis. It proposes that the AIDS pandemic was sparked by the vaccination of approximately one million Africans with an experimental oral polio vaccine called CHAT. [Vaccinations photo.] The 27 known African trials[vi] of CHAT vaccine occurred between the years of 1957 and 1960, in the central African countries now known as Democratic Republic of Congo (DRC), Burundi and Rwanda. In the fifties, these countries were all administered by Belgium.[vii]

By the latter half of the 1950s, virtually all polio vaccines were being grown in a substrate of monkey kidney tissue culture. Most of the major polio vaccine developers -- Sabin, Salk, Cox, Lepine and Gear -- identified the species they were using in one or more of their early publications; (the first three used rhesus and cynomolgus macaques from Asia, the last two used baboons and African green monkeys from Africa). Alone of the major manufacturers, the developer of CHAT vaccine, Hilary Koprowski, never revealed the species of primate he had used in any publication of the fifties.[viii]

For a number of reasons, I began to suspect that Koprowski and/or his collaborators might have used cells from the common chimpanzee to make some of the CHAT vaccine batches fed in Africa.

One reason for my suspicions was that at the time he developed CHAT, Koprowski -- in collaboration with Belgian researchers in the DRC (the then-Belgian Congo) -- had just opened a huge chimpanzee colony at a place called Lindi, a few kilometres outside Stanleyville (now Kisangani). [Lindi sign photo.] There is almost nothing in the published literature about the polio work which was carried out at Lindi, and despite claims to the contrary,[ix] the research there was conducted under a veil of secrecy.[x] However, before long I learnt that more than 400 chimpanzees had been present at the camp during the first twenty months of its existence, in 1956-1958.[xi]

A further reason involved the epidemiology of HIV and AIDS, for many of the places where CHAT was administered in Africa (but not in Europe, where more than eight million people were vaccinated) were, ominously, the very places where the virus and associated syndrome first appeared.[xii]

[Map of vaccinations and early AIDS cases, mapped on all Africa map.] Outside Africa (in the US, Europe and Haiti) the first evidence of AIDS emerged in 1978.[xiii] But within Africa, the epidemic began at least five years earlier. I documented sixteen African cases (mainly clinically-defined) in which first symptoms appeared between 1973 and 1977. Interestingly, every one of these sixteen cases involved people from the DRC, Burundi and Rwanda, (or else foreigners infected there).

For the period 1978-1980, I documented 23 further African cases, almost all from the same three former Belgian colonies. It was only in 1980 that a few cases began emerging in adjoining countries, like Uganda, Tanzania and Zambia.[xiv]

[AIDS versus CHAT Congo map] When I mapped the location of those early African AIDS cases, I discovered a remarkable fact. Thirty one of these cases could be linked to a specific city, town or village, and of these, 68% came from places where this experimental vaccine, CHAT, had been fed in the 1957-1960 period. (This compares with 42% for Kinshasa, the city that features in both major theories of AIDS origin. It was a CHAT vaccination site, but it is also viewed as a hub in the natural transfer theory.)[xv]

[Map of Congo etc, showing 16 HIV-1 sites.] I then went on to map the earliest evidence of HIV-1 Group M infection in Africa for the years up to 1981.[xvi] Altogether there are sixteen sites in Africa for which we have evidence that HIV-1 Group M was present between 1959 and 1981.[xvii] And nine of these sixteen sites are places where CHAT vaccine was fed in 1957-1960.

Through 1981, there are 70 instances of African Group M infection which can be linked to a town or village, of which 30% come from Kinshasa. However, there is a far stronger correlation, for 76% of these infected sera come from cities, towns or villages where CHAT vaccine was fed in the late fifties.

On the basis of these correlations, and of considerable circumstantial evidence,[xviii] I proposed that batches of the vaccine fed in Africa might have been prepared in chimpanzee cells which contained SIV,[xix] and that the 27 CHAT vaccination campaigns conducted before independence in the DRC, Rwanda and Burundi might have allowed chimpanzee SIV to infect one or several of the vaccinees.[xx]

As I say, The River was published in August 1999, and by December of that year it was evident that the book had sparked a major controversy.

In that same month, Bill Hamilton approached both the Royal Society in London and this academy, asking both institutions to host conferences about the origins of HIV and AIDS, and the implications for modern medicine. Before he left for Kisangani in January 2000, the London conference had been approved, and two co-organisers appointed. What happened after his tragic death in March 2000 is a complicated and largely unpleasant story, and one that is better told in another forum. Suffice it to say that largely, I believe, at the behest of one of the remaining organisers, Professor Robin Weiss, the balance of the meeting was subtly but irrevocably tilted against the OPV theory.[xxi]

At the meeting, the results of the testing of certain archival CHAT samples released by the Wistar Institute were announced: they were found not to contain any HIV, SIV or chimpanzee DNA.[xxii] In vain did I argue that the tests were relatively meaningless, because none of the samples tested came from batches that had been prepared for use in Africa.[xxiii]

Most of the scientific and lay press overlooked this point, and concluded that CHAT vaccine had been vindicated. These conclusions were reinforced seven months later, when Nature and Science published three brief formal reports of the CHAT vaccine testing, together with a short theoretical article about Group M phylogenetics.[xxiv] "Disputed AIDS theory dies its final death", ran the headline in Science.[xxv] "Polio vaccines exonerated", was the title of Robin Weissās commentary in Nature, which ended with a memorable sound-bite. "Some beautiful facts", wrote Weiss, "have destroyed an ugly theory".[xxvi]

It was an irresponsible claim, for no relevant facts (beautiful or otherwise) had been presented, and no theory destroyed.

But it was also, more significantly, a false claim. How can I say this? Because two weeks before Dr Weiss published his comments in Nature, I was visiting Kisangani, where (rather to my surprise) I discovered that, forty years earlier, CHAT vaccine had been produced in the local medical laboratory, almost certainly in a culture of chimpanzee cells.

On my first visit to Kisangani, with Bill Hamilton in June 1999, I only managed to locate one significant witness. But on this visit, in April 2001, I enjoyed more success. [Chimp dissection photo.] First I came across Joseph, the so-called "nurse" of Lindi camp, the man who had helped the Belgian doctors perform autopsies on the chimpanzees.[xxvii] It was he who had sacrificed the chimps, opened them up, and who then carried out many of the initial gross dissections.[xxviii] He said that altogether, in the three and a half years of the camp's existence, Lindi had housed over 600 chimps.[xxix] All were eventually sacrificed, apart from the relatively small number which died of natural causes, and apart from the final 60, which were taken elsewhere when the camp closed.

For most of this time, he said, the doctor performing the autopsies had been Paul Osterrieth, the head of the new virus laboratory that had opened in Stanleyville in September 1957.[xxx] During these autopsies, the major organs (including the kidneys) were taken away in sealed containers -- and were then sent abroad, mostly to America. Sometimes the organs would be removed while the animal was anaesthetised, but still living. Large quantities of blood were also taken.[xxxi]

Over the next few days, I spoke with two of the men who had worked with Dr Osterrieth in his virus lab from 1958 to 1960. The first of these assistants[xxxii] had been speaking about Osterrieth for several minutes when he quite casually volunteered: "and he was also making the polio vaccines in the laboratory". Hiding my astonishment, I asked him how this had been done. What happened first, he said, was that an order would come from the Provincial Director of Medicine that vaccine was to be prepared for this or that town. When this happened, Osterrieth would stay behind in his lab in the evenings, after the other workers had gone home. (This was Osterrieth's own lab, he added, the one which was kept sterile, and which nobody else was allowed to enter. This was also where Osterrieth used to take the bloods from the chimpanzees, to spin them down into sera.)

When his boss had finished preparing the vaccine, the assistant would help transfer it into small stoppered phials. Sometimes he also helped administer the vaccines -- and this was always done by mouth.[xxxiii] The vaccinations continued up to Independence in 1960, he said, whenever an order came through from the Medecin Provincial. He added that the other doctors in the lab all knew that Osterrieth was making the polio vaccine.

One place he personally recalled helping to vaccinate was at Stanleyville military camp, on the south side of the river. This was significant because, unusually, the vaccination at this site was documented in a letter in the Belgian government archives. Over 3,000 men, women and children were vaccinated here on February 27, 1958 -- namely Koprowski Day, the eighth anniversary of the date when the developer of CHAT first fed OPV to non-immune subjects.[xxxiv]

Shortly after this, the proceedings of the Royal Society meeting were published,[xxxv] and they included an "additional contribution" by Dr Osterrieth, entitled "Vaccine could not have been prepared in Stanleyville".[xxxvi] In this article, and in statements quoted in articles by Stanley Plotkin,[xxxvii] Dr Osterrieth made a number of responses to different parts of my book.

He stated that after receiving training in tissue culture techniques in the USA between October 1957 and January 1958, he returned to Stanleyville in February 1958 with the aim of setting up a cell culture laboratory.[xxxviii] He said that as far as he recalled, it took several months before he succeeded in producing cultures from baboon kidneys and from HeLa cells. He added that he tried to make tissue culture from the kidneys of other small monkeys, but failed, and that trypsin was uniformly used to disperse the cells. He stated that when he was not present in his own lab, the room was locked, for fear of contamination of tissue culture, and that nobody else had access to the virology lab. He stated that autopsies of chimps were never done inside the main medical laboratories, and went on: "I have no knowledge of polio vaccine being diluted or distributed into smaller flasks at the Stanleyville laboratories, and in any case it was never done in my laboratory." Finally, he stated categorically that at no point did he ever attempt to make cell cultures from chimpanzee tissues.[xxxix]

How are we to resolve these differences? Are we to disbelieve the assistant's account, perhaps because it comes from an African technician, rather than a Western doctor?[xl]

On the contrary, I would propose that the assistant's testimony is both precise and believable -- and that he is very clear about what he himself did or did not see or do. This contrasts with Dr Osterrieth's various accounts, which contain anomalies, gaps and contradictions.[xli] Furthermore, different aspects of the assistant's account are confirmed by other witnesses from Lindi, and from the medical lab. By contrast, if Dr Osterrieth's latest account is accurate, then four or five different individuals, both African and American, have to be either lying, or comprehensively mistaken.

I recently made the remarkable discovery that making a further passage of CHAT in the lab closest to the vaccination site was standard practice in the late fifties -- even though there are no specific references to it in the published literature. This had twin benefits, in that it amplified the quantity of vaccine, and potentially boosted the titre (which might otherwise have dropped during transportation to the recipient lab). This in turn meant that less vaccine had to be transported,[xlii] and that more persons could be vaccinated. A careful review of the papers about the European CHAT vaccinations, in which some eight million persons were fed, revealed that this must certainly have happened in Poland, and almost certainly in Croatia and Switzerland.

Furthermore, when I reviewed the transcript of one of my interviews with Hilary Koprowski, I realised that -- although he was extremely cagey about matters pertaining to the African trials -- he volunteered on more than one occasion that several labs around the world had produced their own versions of CHAT, either from seed pools, or by amplifying the vaccines themselves.[xliii] He was effectively pointing out that anyone, once they had a sample of a live vaccine like OPV, could have produced further vaccine locally.[xliv]

But at this point, let us return to Osterrieth. If his version of events is not accurate, and if CHAT vaccine was being prepared in Stanleyville, then how might it have been made? We now know from several sources that Osterrieth was obtaining large amounts of blood, and large numbers of organs (including kidneys) from the Lindi chimps. And we are lucky enough to have a document which gives a good indication about how such a vaccine might have been prepared. [AFEB paper.] This page is from a paper published by the U.S. Armed Forces Epidemiology Board (AFEB) in 1959.[xlv] It concerns the research into hepatitis in chimpanzees carried out by a Philadelphia scientist, Fritz Deinhardt, who arrived in Stanleyville on February 1st, 1958, and stayed until the end of April. He was based in Paul Osterrieth's virology lab.

In order to conduct hepatitis research in vitro, Dr Deinhardt wanted to transport living chimpanzee cells back to Philadelphia.[xlvi] And so minced chimpanzee kidneys were mixed with chimpanzee sera and Hanks' solution, and the material was flown back to the US in an insulated box. The cells were not treated with trypsin until they arrived in Philadelphia.[xlvii]

In his latest article, Dr Osterrieth refers to these preparations as "cultures" -- by which he clearly means Maitland-type suspended cell cultures, rather than the more usual trypsinised monolayer cultures.[xlviii] Osterrieth adds that he cannot recall exactly when these cultures were made, but insists that none were retained in Stanleyville.[xlix]

However, on the question of timing, I can offer some help, because Dr Deinhardt's former boss, Professor Gertrude Henle, told me unequivocally that Deinhardt himself sent the chimp kidney shipments back by air during his time in Africa.[l]

This means that between February and April 1958 either Osterrieth, or Deinhardt, or both, was (or were) producing Maitland suspended cell cultures in the Stanleyville virology lab, and that they were almost certainly grown in chimp kidney cells and nourished by chimp sera.[li]

This, of course, is the exact period for which we have an eye-witness report of Dr Osterrieth "making polio vaccine" -- a report which is linked to a vaccination on a specific date, February 27, 1958, at the military camp in Stanleyville.[lii]

So, was this relatively primitive chimpanzee cell culture used to make fresh batches of CHAT? On the basis of Osterrieth's own evidence, there would seem to have been no other cell culture available in his lab during this period. As well as the chimp cell melange, the only additional items required to make a perfectly good tissue culture for polio vaccine production would have been a few drops of penicillin and streptomycin.[liii] A former scientist from the Wistar Institute, who wishes to remain nameless, has assured me that to make a new batch of vaccine from scratch (making a cell culture, inoculating with a small quantity of vaccine, and checking the titre) would have taken two weeks at most. Even in the fifties, he added, this would have been a simple task, a kitchen sink operation.[liv]

Furthermore, for those who prefer their witnesses to be Western scientists rather than African technicians, there are two Belgian doctors who were intimately involved with the CHAT vaccinations who have both testified that chimpanzees were used to prepare the vaccines. In both instances, the witnesses later modified their statements. But the precise testimony from Osterrieth's assistant lends fresh significance to the immediate, instinctive answers which these two doctors gave, before they had a chance to reflect on the implications.[lv]

Others must make up their own minds, but I believe that Dr Osterrieth's unsupported claims that "vaccine could not have been prepared in Stanleyville" are simply not credible. I also believe, on the basis of evidence from multiple sources, that CHAT was in all likelihood passaged there in chimpanzee cells.

It is worth noting that a fifties centrifuge would not have been able to remove all the macrophages and lymphocytes (those target cells for SIVs and HIVs) from the serum. And because trypsin was not used in these cultures, its tendency to inactivate SIV and HIV would not have been a factor.[lvi] Furthermore, since cells from more than one chimpanzee may well have been involved, it may be that more than one chimp SIV would have contaminated the cultures -- which raises the possibility of in vitro recombination.

Altogether, five of the sixteen places where HIV-1 was detected in Africa before 1981[lvii] had CHAT vaccinations in this key period of February to April 1958.[lviii] Three of these were villages or small towns of less than 5,000 people, which are not the type of places one would expect to be infected at an early stage by normal dissemination of the virus.

If this scenario has merit, then where does responsibility lie? Of course, since AIDS was unknown in the fifties, nobody knew that they might be assisting an SIV to make a cross-species jump. But it was well known that primates were host to adventitious viruses, so it must also have been realised that to use a new species as substrate was potentially dangerous.

Were these decisions taken solely by Dr Paul Osterrieth? Or does the fact that, weeks earlier, he was trained in cell culture techniques at the Wistar Institute suggest that the developers of CHAT vaccine, doctors Hilary Koprowski and Stanley Plotkin, might also have been involved?

Just as worrying as the fact that several people who were involved with this story back in the fifties have been less than candid about their involvement, is the further evidence that, since 1999, there has been a substantial attempt to whitewash these issues made by several parties, especially those from the U.S and Belgium. Some of those involved have done themselves great discredit.[lix]

One particular instance must be related, because of its alarming implications. I have discovered that a professor associated with The University of Leuven and the Rega Institute (two Belgian institutions which were conducting research into CHAT in the late fifties and early sixties) has recently visited Kisangani, where he obtained pathology samples from the years 1955-1958, and records relevant to those samples. This was done without the knowledge or agreement of the owner of the samples. After a complaint was made, the slides and registers were promptly returned, but it appears that some of the slides may have gone missing. The Rector of the University of Kisangani (who has links with the University of Leuven) is now refusing access to these materials except to those parties whom he approves.

It should be borne in mind that those pathology slides pertain to the period both before and after the CHAT vaccinations had begun. So high have the stakes become, and so widespread the desire to persuade the world that the OPV theory is without merit, that I believe the example provided by this incident must raise questions about any HIV-infected blood or tissue specimen which may in future emerge from before the year 1956, when CHAT vaccine was developed. It underlines the fact that the provenance of any such sample would need to be very carefully examined.

It would be nice to believe that some of the protagonists in the CHAT story might, at this point, be a little more frank about the roles they have played. However, given the history, I am not optimistic.[lx]

However exciting it may be for me personally to have my long-standing hunch about CHAT vaccine confirmed, it is important to acknowledge that it has not been proved that CHAT vaccine sparked the AIDS epidemic. That remains a hypothesis.

However, let me close by returning to the various scientific arguments that have been used against OPV, the so-called "disproofs" of the theory, and seeing which of them still have merit.

Firstly, the tests that were carried out on the CHAT samples made at the Wistar Institute may now be set aside, for they are clearly irrelevant to determining the status of the African-made vaccine.[lxi]

Secondly, the fact that batches of CHAT appear to have been grown in chimp cells and sera (and without trypsin), renders irrelevant the long multiplications of Professor John Beale, who calculated the chances of a hypothetical SIV surviving through to the final vaccine as being many trillions to one against.[lxii] If a proper protocol for the Stanleyville vaccine is ever released, then perhaps some appropriate calculations -- or experiments -- can be done.

Third, Beatrice Hahn's hunch that the only true ancestor of Group M is the chimpanzee from west central Africa is, I believe, unproven, in that not nearly enough chimpanzees and bonobos from the central African rain forest have been sampled.[lxiii] More pragmatically, however, we know that at least two Lindi chimps came from zoos, and one from the district of Coquilhatville (now Mbandaka), which lies just as close to Hahn's west central African chimps as to the DRC chimpanzees.[lxiv] [Map of chimp distribution.] Co-caging was routine at Lindi, most notably co-caging between chimpanzees (Pan troglodytes) and pygmy chimpanzees (Pan paniscus), and there was also one large cage where up to ten animals at a time could play together. For this reason, even if Hahn is right about the precursor host, the presence at Lindi of even one west central African chimp would be enough to establish that the SIV precursor to Group M (from whichever chimp subspecies that may be) could have been present, and spreading, at the camp.[lxv]

Fourthly, the natural transfer school proposes that Leopoldville/Kinshasa may have represented an early hub for HIV-1(M), and the other early AIDS cases we see simply represent dissemination from that hub. But look at the stats. 42% of African AIDS cases through 1980, and 45% of African HIV-1(M) infections through 1980, come from that city.[lxvi] But since this is the only large city in the DRC (with upwards of three million people by the early 80s), these are exactly the sort of figures which the OPV theory would predict, whether or not contaminated vaccine batches were administered there. What the Kinshasa hub theory ignores are the other places where disease and virus were detected, which are predominantly places where CHAT vaccine was fed. Through 1980, 68% of African AIDS cases, and 85% of African HIV-1(M) infections, came from CHAT-vaccinated places.[lxvii]

So we come down to the most significant argument against OPV, which concerns the date at which chimp SIV might have crossed into humans. This is the issue which lies at the core of the debate between the natural transfer and OPV theories. The phylogenetic analysis of such scientists as Paul Sharp, Bette Korber and Anne-Mieke Vandamme[lxviii] suggests that the most recent common ancestor of today's Group M viruses existed in the 1930s, with 95% confidence intervals that extend roughly ten years, plus or minus. And so these geneticists conclude that the last common ancestor of Group M must have existed at least a decade before the beginning of the CHAT polio vaccine trials in 1957. They and their supporters maintain that this disproves the oral poliovaccine theory -- or renders it very unlikely.

However, an increasing number of eminent scientists in the fields of genetics, molecular biology and virology suspect that the phylogeneticists may all be making similar assumptions in support of their calculations, and that some of these assumptions may be wrong.[lxix] Most particularly, they doubt that phylogenetic analysis is an appropriate method for dealing with recombination, which is a major element of retroviral evolution, and suspect that the phylogeneticists' attempts to make allowances for recombination are, in reality, little more than "educated guesses".[lxx]

I am very pleased that later today, we are going to hear from Mikkel Schierup, a geneticist who is not afraid to express an interpretation that is different to the Hahn/Sharp/Korber group. In particular, Schierup states, "recombination events occurring early in the evolution are very difficult, if not impossible, to detect". He proposes that failing to make proper allowances for recombination may lead phylogeneticists to either under-estimate or over-estimate the most recent common ancestor, and that the error bars have not been set far enough apart. He further proposes that if two divergent chimp SIV sequences were transferred to humans and then recombined, this alone could have created the range of Group M variants seen today.

This last concept potentially aligns rather well with the OPV theory. This is because recombination between two divergent chimp SIVs could be exactly what happened, either in a vaccine tissue culture made from chimp cells, or else in a vaccinated town, soon after two different chimp SIV sequences were transferred to different vaccinees.

Dr Schierup, by the way, is also a sceptic. He tells me that he thinks the OPV theory is "highly improbable. But so is the alternative".

It seems to me that the dating question, which remains the main argument against the OPV theory, is still anything but decided. It also seems to me that anyone who tries to insist that the OPV theory is "dead" on the basis of phylogenetic analysis (or inappropriate testing of vaccine samples) is motivated more by politics than by science.[lxxi]

So there we have it. There is evidence that batches of CHAT oral polio vaccine were prepared locally in the virology lab in Stanleyville, Belgian Congo, and were then used to vaccinate up to a million Africans in the late fifties. This local preparation of polio vaccine was not unusual -- in fact it was normal practice for CHAT vaccine originating from America to be passaged again (for instance in European labs) in order to boost the titre, so that more people could be vaccinated. What was unusual in this case, however, was the cells and sera which were available to do this, which -- in Stanleyville -- came from chimpanzees. The very close correlations between the places where CHAT was fed in Africa and the first appearances of HIV-1 and AIDS suggest that the vaccine may have been the vehicle whereby chimp SIVs were first transferred to humans, thus giving birth to HIV-1 Group M, and the AIDS pandemic. The case is certainly not proven. But there are flaws and shortcomings in every one of the arguments used to counter the OPV theory -- including the much-vaunted dating argument. Claims that the OPV theory has been "destroyed" are simply untrue.

I believe that this new information about CHAT production in the Belgian Congo in the 1950s is of enormous importance, and not only with regard to the OPV theory, and the question of how AIDS may have started. It also raises important ethical questions about the ways in which modern research is funded; the ways in which members of the scientific establishment (and those who produce scientific journals) respond to theories which they find difficult or threatening; and the ways in which experimental trials have been, and are still being, conducted in the developing world.[lxxii]

As I warned at the beginning, my speech has been robust, but it has also been based on the abiding scientific principle of honest and unbiased research.[lxxiii]

Professors of the academy, gentlemen, ladies, scientists·.thankyou for inviting a non-scientist to Rome to speak to you.

[i] Hooper, E., The River: A Journey to the Source of HIV and AIDS. Boston/London: Little, Brown/Allen Lane -- Penguin Press; 1999. A paperback edition published in 2000 contains a rewritten postscript; page references from page 827 onwards are therefore different in the two editions.

[ii] To date, AIDS has caused the deaths of over 20 million people, and the infection of more than 60 million with the causative virus, HIV-1 Group M.

[iii] Huet T., Wain-Hobson S., "Genetic Organization of a Chimpanzee Lentivirus Related to HIV-1"; Nature; 1990; 345; 356-359.

[iv] Notably Beatrice Hahn, Paul Sharp and Bette Korber (but also enthusiastically propounded by others, like Stanley Plotkin and Hilary Koprowski).

[v] For the cut hunter school, the recency of the epidemic is explained by new developments in the mid twentieth century, such as urbanisation and more liberal sexual mores, or else the emergence (and ill-advised reuse) of disposable needles, allowing the chimpanzee virus, once transferred, the new opportunity of being passed parenterally from human to human. At its most basic, the natural transfer theory of a casual chimp-to-human zoonosis seems quite reasonable, even if it is impossible to prove or disprove. On the other hand, the theory also has certain innate logistical problems, such as why the initial infection spread from Congo Brazzaville, Gabon or Cameroon southwards to Kinshasa (rather than infecting people locally); and why for the next forty-odd years the burgeoning epidemic spread only eastwards, rather than to the south or north. [More basically, the 'cut hunter' theory, at least my version of it, holds that the origin of HIV-1 is not all that recent; it is only the "epidemic" aspect that dates to the postwar period. Spread from former French Equatorial Africa southward and eastward to Kinshasha and Kisangani (and beyond, into Rwanda) is fully consistent with established major trade networks. The lack of "local" infections is worth considering, but recall that Gabon and northern Congo Brazzaville are among the least-densely populated areas in Africa, with very little medical care in the early part of the century. What we are looking at is not absence of local infections, but absence of medical records of local infections, in a region where such records would be surprising. Bottom line: both theories handle these aspects of the early epidemiology equally well/poorly. -- Jim Moore]

[vi] In several instances, I have updated the data published in The River. Here I have omitted one of the 28 CHAT trials that feature in the book (trial #22, of 64,000 persons at Lubudi, or Kabare-Lubudi), because I agree with Stanley Plotkin that there is no evidence that it ever took place. Dr Plotkin, however, should not get carried away, for despite his efforts this is the only error of any significance that he has managed to identify in the book. In my own defence, I should point out that Kabare-Lubudi was apparently mooted as a forthcoming trial at a 1959 press conference at which Plotkin himself was one of the three major speakers. Furthermore, accepting that the trial is not proved to have occurred is not the same as accepting that it did not occur. (Kabare and Lubudi territories are indeed hundreds of kilometres apart, as Plotkin observes, but they were also, in 1959, the sites of two of the Belgian Congoās three major cement factories. I still suspect that the trial may have taken place, perhaps at the behest of the chief medic of the cement company.) But for now, I agree that without proof, this trial should be omitted from the list.

[vii] The Belgian Congo (now the DRC) was a colony, while Ruanda-Urundi (now Rwanda and Burundi) was a UN trusteeship administered by Belgium.

[viii] The River, pp 387-389.

[ix] Plotkin S.A. "Untruths and Consequences: the false hypothesis linking CHAT type 1 polio vaccination to the origin of human immunodeficiency virus". Phil. Trans. R. Soc. Lond. B, 2001; 356, 815-823. "The purpose of the camp was not at all mysterious", writes Plotkin, which conflicts with the testimony of the Lindi workers, as reported in the present article.

[x] With the sole exception of a retrospective article published in 1967 by the former director of the Laboratoire Medicale de Stanleyville, Ghislain Courtois, there are only a few sentences published about the work carried out at Lindi camp, and these include next-to-no information about the polio work, and nothing at all about the sacrifice programme. [G. Courtois, "Sur la realisation dāune singerie de chimpanzes au Congo"; Symposium International sur lāavenir des animauz des laboratoire, Lyon, September 18-20, 1966 (Lyon, Institut Merieux, 1967, pp. 235-244).] The annual reports of the Laboratoire Medicale de Stanleyville reveal that there was vaccination, vaccination and challenge, and intraspinal safety testing of the polio vaccines at Lindi, but nothing more. (Even this work is extraordinary. The vaccination and challenge involved vaccinating with a Type 1 polio vaccine, to see if it could protect against challenge with virulent Type 2 poliovirus -- a preoccupation of Koprowski's , perhaps not unconnected to the fact that for many years he had problems with his Type 2 vaccine strains. And the vaccine used was not even CHAT, but rather his previous Type 1 vaccine, SM N-90. This work was done three months after Koprowski had parted company from his previous employers, Lederle, who officially owned the SM N-90 strain.) The lack of information about the research conducted at Lindi is very striking, and even some of the Belgians who used to work in the Stanleyville lab commented upon it. During the period the camp was open, visitors to Lindi were discouraged, and apart from the Belgian and American doctors and their African assistants, nobody was allowed inside the second hangar, which housed the chimps that were scheduled for experimentation. Despite this secrecy, certain visitors discovered interesting details. For instance, early in 1960 a visiting Dutch primatologist, Adriaan Kortlandt, was told that 86 pygmy chimps had died in 3 weeks in the course of the polio research, and that he should not ask too many questions on the subject, because if he did, he "might cut [his] fingers". It appears that all biomedical samples pertaining to this research have now been lost or discarded. Furthermore, all Koprowski's records about Lindi camp, and the research on his vaccines conducted there, have apparently been "lost in a move", while the relevant archives in the polio correspondence file in the Belgian Ministry of Foreign Affairs archives section for the key period (November 1956 to June 1958) are missing. See River, chapter 52, pp 708-723.

[xi] Another reason for my suspicions was that for his previous Type 1 polio vaccine, SM, Koprowski had, in articles published in 1956 and 1957, misreported the medium he had been using to produce the vaccine. He wrote that he had been using chick embryo tissue culture as a final substrate for the vaccine, when he had in fact been using monkey kidney tissue culture of unknown species. [River, p. 385] Koprowski is in many ways a ground-breaking scientist, one not afraid to step where others fear to tread, but there are also several examples in The River of occasions when he appears to have displayed recklessness. One such was his involvement in the staging of a field trial of an early genetically modified rabies vaccine in Argentina in the mid-eighties, without the permission or approval of the Argentine government. The London Times, in a leader, described this as a "reckless and illegal release". [River, p. 449]

[xii] Even before I came across the OPV theory, I had spent several months documenting the earliest cases of HIV-1 infection and AIDS which were attributable to Group M. First I did this on a global level. The very first serologically confirmed AIDS case, a Norwegian merchant seaman who developed symptoms in 1966 and died in 1976, turned out to be caused not by Group M, but by a rarer HIV-1 variant, Group O. River, pp. 772-774.

[xiii] Those very few European and American cases from before 1978 all appear to have been infected in Africa -- and, more specifically, in the DRC, the former Belgian Congo. There are two possible exceptions, only one of which is confirmed by serology -- this being a girl born in New Jersey in 1973 or 1974, who was clearly immunocompromised soon after birth, and who died of AIDS in 1979. The girlās mother was a drug-injecting 16-year-old with multiple partners, who must have been born between late 1956 and 1958. The mother had thrombocytopenia at the time of the girlās birth, suggesting that she might have passed HIV infection vertically to her daughter. In The River, I proposed that the mother might have been one of those infants who was born at Clinton prison, the major long-stay penitentiary for female prisoners in New Jersey, where almost every baby born between late 1956 and 1958 was vaccinated with one or more of Koprowski's OPVs, most of which were experimental. In his speech to the Royal Society, Dr Plotkin rejected this hypothesis, explaining that he had approached the pediatrician who had tended to the young girl, and discovered that the motherās name did not match that of any of the Clinton infants from the 50s. That appeared to have settled the matter. However, in June 2001 I was approached by a man who knew that he had been born at Clinton prison, and suspected that he might have been one of the OPV vaccinees. From certain data he provided, I was able to confirm that he had indeed been vaccinated. However, this man had been adopted at age two, and had been given the family name of his adopted parents. At the time he approached me, he did not know his original family name. Other vaccinated Clinton infants may similarly have had their names changed following adoption, and may not even know this fact. For this reason, Plotkin's "refutation" of a link with CHAT in this instance may not be a refutation at all.

[xiv] All 39 of these early African cases had been documented retrospectively as likely cases of AIDS by the doctors involved, either in the medical literature, in books or in unpublished articles. For 9 of the 39, retrospective serology had confirmed HIV-1 infection. Two additional Burundian cases of AIDS, from Muramvya (1976) and Bujumbura (1980), have been added to the list on pages 746-747 of The River, and one case (#2) has been omitted from that list, since it relates to Group O infection. In addition, it seems that details of one AIDS case (#32) were somehow omitted from this table during the final production stages of the book. The relevant details should read: 1980; Congolese; 21; female; Congo; herpes, candidiasis.

[xv] At the Royal Society conference a Belgian-born epidemiologist now working for the CDC, Kevin De Cock, implied that the pattern of early HIV-1 infection in Africa simply reflected the spread of the virus up-river from Leopoldville/Kinshasa. His conclusions were immediately seized upon by doctors Koprowski and Plotkin to support their own arguments. But De Cock was selective in the data he examined. He decided to use my AIDS data from the Congo, but (without explanation) chose to ignore the equally important AIDS data from Rwanda and Burundi. And he effectively ignored the equivalent data relating to HIV-1(M). He was quite correct in observing that the largest numbers of early African AIDS cases came from Kinshasa, and that this might reflect not only the early arrival of HIV-1 in that city, but also sampling bias. (In fact, 42% of AIDS cases through 1980, and 30% of HIV infections through 1981, come from Kinshasa.) But since this is the only large city in the AIDS epicentre (with upwards of three million population in the 1980s), that is exactly what one might expect, whichever hypothesis one subscribes to. What Professor De Cock ignored were the other places where the virus and disease were detected. It is my belief that what evidence we have of the existence of Group M viruses up to and including 1980 is not suggestive of random spread, but instead reflects rather closely the venues where CHAT vaccine had earlier been fed. De Cockās analysis stuck doggedly to the line that even apparent epidemiological associations do not establish causality. This is undeniable, but equally he seemed determined not to address even the possibility that a significant association might exist. His paper was delineated as "US government work in the public domain". [De Cock, K.M., "Epidemiology and the emergence of human immunodeficiency virus and acquired immune deficiency syndrome", Phil. Trans. R. Soc. Lond. B; 2001; 356; 795-798.]

[xvi] The earliest HIV-1 sample is from Leopoldville (nowadays Kinshasa in the DRC) and dates from 1959. Of course, as Kevin De Cock emphasised, the sampling has been haphazard, and only provides a limited snapshot from the era. None the less, the data does give some useful indications about where HIV-1(M) was present (and where absent) in these early years. These figures pertain both to those whose blood was sampled in the years up to 1981, and later tested retrospectively for HIV-1 infection, and to those who later tested HIV-1-positive, but for whom it could be proved that infection must have begun by 1981 or before.

[xvii] Twelve of the sixteen are from the DRC, Burundi and Rwanda. The remaining four sites, in Tanzania, Kenya, Congo Brazzaville and Senegal, begin to show evidence of Group M only in the early 1980s, when the virus started to spread across Africa.

[xviii] Among the additional circumstantial evidence are details such as these: Alexandre Jezierski, a Polish vet working at a tiny lab in eastern Congo (with whom Hilary Koprowski says he spent 3 days in 1957) had previously spent six years growing polioviruses in the cells of 15 different African primates (including chimps). He reported that poliovirus growth in chimp tissue culture had been "very good". He went on to make both killed and live polio vaccines in the kidneys of three of these fifteen species, and he did some of his titrations in chimpanzee kidney tissue culture. At this time, chimps were available in the Congo in huge numbers, and for about $5 each. In local newspaper articles, it was declared that the chimp research at Lindi had allowed the researchers to "put the finishing touches" to the vaccine.

[xix] If the vaccine had been prepared in chimp cells, as I hypothesised, we know that roughly 2-3% of juvenile chimpanzees in the wild are infected with SIV. Furthermore, co-caging practices at Lindi (which included a large communal cage for play) might well have allowed SIV to spread within the camp. Stanley Plotkin argues that chimps get SIV infection by the sexual route, and that because the Lindi chimps were juveniles, they are unlikely to have been infected. In fact, there is no available data on the means of transmission of SIV between chimps. But the fact that the first four SIV infections detected in chimps were all in juveniles (or animals which must have been infected while juveniles) suggests that the parenteral and perinatal routes may be significant.

[xx] As I freely admitted in the book, and in interviews, there was no clinching evidence. I had not even proved that CHAT vaccine had been made in chimpanzee cells. However, many of those who read the book concluded that OPV was a plausible explanation for how the AIDS pandemic might have begun. Shortly before his death, Bill Hamilton wrote to a colleague that, in his opinion, there was a 95% probability that the hypothesis was correct.

[xxi] None the less, a few aspects of this sorry tale need to be recounted here. The first evidence of the degree of concern which the book had aroused was revealed in February 2000, while Bill Hamilton was still lying in a coma. There was concerted pressure on those involved with the London meeting from across the Atlantic, including threatened withdrawals by those who had previously agreed to speak, propagandist letters written to newspapers, and private approaches made to the organisers and other senior Royal Society figures by their counterparts in the National Academy of Sciences, including at least one Nobelist. These approaches were characterised by claims that the origins debate was harming the reputation of Science, and the future of vaccination programmes in the Third World. When the conference took place in September 2000, both the principal developers of CHAT vaccine, Stanley Plotkin and Hilary Koprowski, gave speeches. Despite having had a year to prepare their arguments, they had been unable to find more than one or two minor errors in the 1100 pages of my book. Instead, they concentrated on trying to discredit both book and author. For instance, they issued three press statements, which were characterised by a high degree of exaggeration, inaccuracy and untruth. [For my analysis of these, see Brian Martinās "origin of AIDS debate" web-site at: http://www.uow.edu.au/arts/sts/bmartin/dissent/documents/AIDS/.] Furthermore, they and their team approached many of those scientists whom I had interviewed, inviting them to modify, or retract, statements which they had already made to me on audio tape. Examples: Dr Gaston Ninane, one of the key protagonists in Stanleyville and at Lindi, was visited in Belgium by Dr Koprowski and two other doctors. At the time, Dr Ninane was in hospital following a serious fall, and he died four months later, apparently from Parkinsonās and Alzheimerās disease. Another elderly witness to the events at Lindi camp was approached by five or six senior Belgian doctors, for whom he eventually signed a statement. Later, embarrassed, he told us he could not recall what he had signed for the Belgian doctors, but he reaffirmed certain key details which conflicted with its contents. A third man has been variously approached by several doctors, including Dr Abel Prinzie, who sent him a typed letter to sign, with his name pencilled at the bottom. He refused to comply, saying that the approach had been "a dishonourable proposition". The people who approached him "have no leg to stand on", he added.

[xxii] By this stage, I was increasingly feeling as if I had been set up. This feeling was only reinforced when, as one of five speakers at the press conference which, surprisingly, had been scheduled to follow immediately after the announcement of the test results (rather than at the end of the conference), I began my allotted three minute speech. Twice within a minute I was interrupted by Professor Weiss, who apparently felt that his brief as co-organiser of the conference extended to controlling what I was able to say to the press. On the second occasion he was shouted down by a reporter.

[xxiii] Although two of the samples tested came from a CHAT pool (13) which had been used in Africa, I pointed out that different batches of such pools of CHAT had been prepared in different laboratories, and in the kidney cells of different species. It was where and how the individual batches had been prepared which was significant.

[xxiv] The word was that three major scientific journals had been competing to publish the results of the Wistar testing, and in the end Nature and Science shared the honours. See 3 articles in Nature; 2001; 410; 1045-1048, plus one article in Science; 2001; 292; 743-744.

[xxv] Cohen J., "Disputed AIDS Theory Dies Its Final Death"; Science; 2001; 292; 615.

[xxvi] Weiss, R.A., "Polio vaccines exonerated"; Nature; 2001; 410; 1035-1036. In this commentary, remarkably, Professor Weiss twice confuses the terms "pool" and "batch", thus obfuscating the key issue about the testing. The hyperbole which characterised the coverage in both Nature and Science, suggested to me (and others) that scientific rationale was being abandoned in an attempt to dispose of an uncomfortable theory. Robin Weissās role in this controversy is interesting, not least because he twice wrote me about the subject before the publication of The River. (We had had some contacts about archival tissue samples some nine years earlier, but nothing since then.) In the first letter, dated June 28, 1999, Weiss wrote that he heard that I was publishing an article or a book on the subject, and that perhaps he could suggest reviewing it for Nature. He also asked me to fill him in on details, adding "Iāve become concerned again, owing to rumours that chimpanzee kidneys may have been used for Koprowski's live attenuated vaccine in the middle 1950s." I wrote back explaining that there was an embargo on the book, and I could not furnish any details about its content until publication. On July 26, 1999, Weiss replied, saying he had a "Perspectives" piece coming out in Science in September or October, in which he would be referencing Beatrice Hahnās study of HIV-1 probably coming from chimpanzees (by natural transfer), and asking if it would be misrepresenting me to add: "Can we be sure that AIDS did not have an iatrogenic, medical origin if chimpanzee kidneys cultures were used in Africa to propagate certain batches of polio virus vaccine? (Hooper, 1999)". This is intriguing, because at this stage I had not seriously considered local African production of CHAT as an option, even if I had (in a late addition to the text of The River) inserted two pages pointing to the particular events that took place in Stanleyville in February 1958, and hypothesising that this might be a possibility. (See River, pp. 789-791, and compare with pp. 720-722, my previous position.) So the second letter suggests that Weissās thinking was well ahead of my own, which renders Weissās current committed opposition to the theory all the more remarkable. I believe that he also briefly referred to the possibility of local vaccine production in Africa in his closing speech at the Royal Society meeting. However, no mention appears in the published version of that speech, which (incidentally) has a far more balanced and reasonable tone than its spoken counterpart. [Weiss, R.A., "Natural and iatrogenic factors in human immunodeficiency virus transmission"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 947-956.]

[xxvii] This came as a very pleasant surprise, because previously I had been informed that this man had died in 1964.

[xxviii] The work was done on a table in the second hangar -- the one which nobody else apart from the Stanleyville doctors and the Lindi camp workers was allowed to enter. For many (though not all) of the operations, the nurse was the only African present.

[xxix] This ties in with my own figure of 416 chimps housed at Lindi during the first 20, very hectic months after the camp opened (June 1956 -- February 1958). It was, however, the first time that I had heard such a high overall total.

[xxx] The virus lab was only one section of the brand new medical lab and animal house which had opened in Stanleyville in September 1957. (Another similar lab opened in the eastern town of Bukavu that same year.) It has never been entirely clear why such huge medical laboratories should have been built so shortly before independence -- and indeed, who paid for them, and for Lindi camp.

[xxxi] This testimony, combined with that of my previous eye-witness from Lindi [for which see: River, 2000, pp 843-846, paperback edition], confirmed that the work there had been conducted in considerable secrecy; apparently nobody outside the camp knew what was going on. What these accounts increasingly suggested was that the research into polio (and hepatitis, etc) conducted at Lindi may have been little more than a bi-product, and that the primary purpose of the camp was to provide large quantities of chimpanzee organs and blood for biomedical research overseas.

[xxxii] After the nature of the approaches made to some other witnesses, I am not presently prepared to identify this man, and certain others who feature in the text. They will be identified in the future.

[xxxiii] This important detail helped confirm that the vaccine in question had indeed been oral polio vaccine; the only OPV present in the Congo at that time was CHAT.

[xxxiv] A second assistant who had not worked so long in the lab confirmed much of the information given by the first assistant, including the fact that Osterrieth was making vaccine in the lab. He seemed uncertain, however, about which vaccine this was, and became distinctly uneasy when asked if he could recall anything about the polio vaccinations. However, this second man did provide an interesting piece of information. At the end of 2000, he said, he had received a letter from Osterrieth, this being the first time he had heard from him for some 40 years. What his old boss wanted to know was which of his former assistants at the virus lab and Lindi camp were still alive, and which had died.

[xxxv] Weiss, R.A., and Wain-Hobson S., editors, "Origins of HIV and the AIDS Epidemic"; Phil. Trans. R. Soc. Lond. B; 2001; 256; 771-977.

[xxxvi] Osterrieth, P.M., "Vaccine could not have been prepared in Stanleyville"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 839. I had intended to approach Dr Osterrieth once more, to give him an opportunity to respond to the testimonies from Kisangani. But then came this latest article, and I realised that there was little point; Osterrieth had already made his definitive statement. In the published version of the Royal Society proceedings, Stanley Plotkin was also allowed to contribute an additional article, which was an attempt to refute some of the new claims that I had made at the conference. [Plotkin, S.A., Teuwen D.E., Prinzie A. and Desmyter J., "Postscript relating to new allegations made by Edward Hooper at The Royal Society Discussion Meeting on 1 September 2000"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 825-829. Hooper, E., "Experimental oral polio vaccines and acquired immune deficiency syndrome"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 803-814.] This postscript featured, inter alia, further witness statements from persons who had previously given clear statements to me and who had now elected to modify their stories, and it ended as follows: "One can anticipate that additional journalistic accusations will appear in the future, but doubtless they will also prove to be farragos". To me, it seemed as if Professor Weiss, as co-editor, had elected to give Plotkin a "free shot", and represented further evidence of his personal bias in this matter.

[xxxvii] Plotkin, S.A., "CHAT Oral Polio Vaccine Was Not the Source of Human Immunodeficiency Virus Type 1 Group M for Humans"; CID, 2001, 32, 1068-84. Plotkin S.A. "Untruths and Consequences: the false hypothesis linking CHAT type 1 polio vaccination to the origin of human immunodeficiency virus". Phil. Trans. R. Soc. Lond. B, 2001; 356, 815-823. Plotkin, S.A., Teuwen D.E., Prinzie A. and Desmyter J., "Postscript relating to new allegations made by Edward Hooper at The Royal Society Discussion Meeting on 1 September 2000"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 825-829. The last of these articles states at the end that "letters cited in this paper will be deposited" at one of two libraries, in Philadelphia and Leuven. However, I would also be interested to see the source documents that Plotkin quotes in "Untruths and Consequences", especially the passage chart, and the March 4, 1958 letter from Koprowski to Jervis, which refers to Ninaneās telegram. Requests to Dr Koprowski to view the latter document have thus far been ignored.

[xxxviii] In an interview in 1994, Dr Osterrieth had given a few additional details. He said that after he had received his training in tissue culture at the CDC and Wistar Institute labs, he returned to Belgium for a few days in January 1958. He then flew out to Stanleyville, arriving a day or two after Fritz Deinhardt. There is documentary evidence that Deinhardt left Philadelphia on January 30, and travelled via Brussels, reaching Stanleyville on February 1. If correct, this means Osterrieth should have arrived in Stanleyville on or around February 3, 1958. [In The River, p. 789, I had previously reported (on the basis of the date given in the 1958 annual report of the Stanleyville lab) that Osterrieth had returned to the lab on February 23. But that date now seems impossible, not least because Osterrieth's assistant started work in the lab on February 12, and says that Osterrieth had started making polio vaccines before that date.] Dr Deinhardtās widow has reported that he booked two seats on the planes, one for himself and one for the "box of shit", this being a cool-box containing faecal specimens from the children of Willowbrook state school, who had been experimentally infected with hepatitis. (The stools were later to be used to infect some of the Lindi chimps.) However, did the box also contain some polio vaccine -- the same vaccine which he later apparently amplified? The one piece of paper which the Wistar Institute has managed to produce about this period demonstrates that the new pool of CHAT, 10A-11 "which is to be used in the 1958 Congo trials", was not ready until the last week of January, 1958. So it would seem likely that a small flask of the new vaccine may have been delivered by Deinhardt, as a service to his close associate, Koprowski, when he flew out from Philadelphia to Stanleyville on the 30th. From the testimony of Osterrieth's assistant, and from documents of the era, we know that Osterrieth's first job would have been to prepare a tissue culture (unless one had been prepared previously and refrigerated), and his second to passage the vaccine from the U.S. in that tissue culture. This would have both increased the available quantity of vaccine, and potentially boosted the titre, so that more people could be vaccinated. As for safety, the original vaccine had been safety tested at the Wistar, as had the sera from 100 of the chimpanzees, which proved to be free of the major known pathogens. All that would have remained would be for his assistants to dilute the vaccine and transfer it into small phials -- which is apparently just what they did, before assisting with the vaccination of Stanleyville military camp on February 27, 1958. Ten days before this, doctors Flack and Jervis, who had been delegated to help supervise the mass vaccination in the Ruzizi valley, arrived at La Guardia airport in New York to set off for the Congo. George Jervisās widow thinks they were probably carrying polio vaccine with them, though this has never been confirmed. However, their flight was delayed by bad weather, which meant that they arrived in Stanleyville on February 20, one day late. If they were carrying vaccine, one wonders in what state it would have been on arrival, especially since the last day of the journey featured long stops in the heat of Athens and Khartoum. If the ice had melted, and the temperature had risen above 4 degrees Centigrade, it may be that by the time they got to Stanleyville, the vaccine titre was greatly reduced. If so, this might be linked to the telegram sent to Koprowski by Ninane on or around March 4, pointing out that they were running short of vaccine for the Ruzizi trial. On the face of it, the strange reply that Dr Plotkin says Koprowski sent to Jervis: "I have advised him [Ninane] to request from you [Jervis] more of liquid Type 1 which will be sent to Usumbura end of March" does not seem to make sense, unless Jervis either had access to, or was himself preparing, locally-made vaccine. Certainly Jervis may have obtained some of the vaccine that Osterrieth made in Stanleyville. On the other hand Jervis was running his own research lab in New York state, and had previously prepared batches of Koprowski polio vaccines in tissue culture, so it is certainly possible that he made up a fresh pool of vaccine at one of the labs in Usumbura or Bukavu, at both of which he spent time during his four weeks in Africa. (Intriguingly, it seems that chimpanzee kidneys were available at the Bujumbura labs during this period. In his "Postscript", Plotkin has denied this, quoting three Belgian doctors who worked there during the fifties, who testify that no monkeys or chimpanzees were ever caged behind the labs. I too have interviewed three Belgian doctors who worked at Bujumbura laboratory during this period, who also deny that chimps or monkeys were ever caged there. However, I have interviewed three others -- African and Belgian -- who have no conceivable vested interests, and who clearly recall that both monkeys and chimps were caged there during the 1956-8 period. One of the latter three has given a detailed account of single kidneys being removed from the chimps (which were then sewn up again), and of the kidneys being sent on to a lab in Butare, Rwanda. This lab was one of only two government labs of that era which officially made human vaccines -- though there are no records of polio vaccines having been made there.)

[xxxix] Osterrieth, P.M., "Vaccine could not have been prepared in Stanleyville"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 839. Plotkin, S.A., "CHAT Oral Polio Vaccine Was Not the Source of Human Immunodeficiency Virus Type 1 Group M for Humans"; CID, 2001, 32, 1068-84. Plotkin S.A. "Untruths and Consequences: the false hypothesis linking CHAT type 1 polio vaccination to the origin of human immunodeficiency virus". Phil. Trans. R. Soc. Lond. B, 2001; 356, 815-823. Plotkin, S.A., Teuwen D.E., Prinzie A. and Desmyter J., "Postscript relating to new allegations made by Edward Hooper at The Royal Society Discussion Meeting on 1 September 2000"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 825-829. In Osterrieth's own article for the Royal Society, there are a few discrepancies from his statements as quoted by Plotkin. At no point in his own article does Osterrieth specifically deny having made cultures from chimpanzee kidneys, or having made cell cultures without trypsinisation, (for instance by the Maitland suspended cell method).

[xl] Dr Koprowski, at the Royal Society meeting, dismissed one of my other African witnesses as a "low technician", a comment which prompted some booing from the audience. My own experience is that African witnesses frequently have more accurate memories of events than Westerners -- which may be partly due to African traditions of oral history.

[xli] Indeed, on one key point, Osterrieth has now given three fundamentally different versions of events. Since 1994, he has claimed (a) that no chimp kidneys were ever sent abroad; (b) that they were only sent to the Childrenās Hospital of Philadelphia and (c), in his latest account, that six kidneys were sent to the Wistar Institute, where CHAT vaccine was developed.

[xlii] Keeping the temperature below 4 degrees Centigrade was always one of the major headaches in moving live vaccines, like CHAT, long distances around the world.

[xliii] A good example of Dr Koprowski's unwillingness to make any definite statement about the African CHAT trials came during my second interview with him in December 1993. At one point, I understood him to have confirmed that doctors Flack and Jervis had flown out from America with the vaccine for the Ruzizi trial in February 1958. But I was wrong, for he snapped back: "I said possibly. This is all invention, hypothesis and fantasy." However, elsewhere in the interview, he confirmed that the labs in Poland and Croatia had made their own vaccines, "though whether as a clone [from a seed lot] or by passage [from a vaccine batch], I donāt remember". A private letter written in 1962 by Drago Ikic to Koprowski's chief lab technician and right-hand-man, Tom Norton, reveals that Croatia had indeed been supplied with CHAT seed-lots. But the evidence suggests that the other European countries which "made their own vaccines", such as Poland, Switzerland and Sweden, did so by onward passage of the CHAT vaccine strains. Elsewhere in the interview, Koprowski said that the Congo, South Africa and Switzerland had received their own vaccine strains, which "actually could be obtained from fifty other sources spread around the world. There was no proprietor. As far as I know there was no patent." The intended implication seemed to be that others (including those in the Congo) had access to his vaccines, and could have passaged them further without his knowledge. At the time I did not believe that CHAT could have been produced locally in Africa, and so failed to appreciate just how significant this implication was. At another point in the interview I asked Koprowski about the adverse results reported by George Dick and David Dane, who had fed his previous polio vaccines, TN and SM, to a total of 190 people in Belfast and Oxford (U.K.) in 1956, and found that they became more virulent (in the case of TN, much more virulent) after passage through the human gut. Koprowski replied that the British doctors had passaged the vaccine virus again in their own lab, implying that any shortcomings in the vaccines were their fault, not his. When I put this to Dick and Dane, they vigorously denied it. The vaccines they fed were exactly what Koprowski had given them, they insisted. But the significant thing was that Koprowski's immediate instinct had been to claim that the vaccine had been passaged further in the recipient lab. I now wonder if Koprowski might have told his overseas collaborators not to mention anything about local production of vaccines in their articles, perhaps because he was afraid that other labs too might get hold of a sample, and then start producing his vaccines without permission (or payment). Did he, perhaps, tell his overseas collaborators that he would take care of things if anything ever went wrong? In reality, however, when things did go wrong (as in Belfast), he tended to blame the recipient lab.

[xliv] Interestingly, it was not only overseas that the CHAT scientists adopted this approach. Stanley Plotkin has recently revealed that even in the Wistar Institute laboratories where CHAT was developed, it was routine to make a fresh CHAT vaccine pool by passaging material from an existing vaccine pool, rather than from a poliovirus seed lot. [Plotkin S.A. "Untruths and Consequences: the false hypothesis linking CHAT type 1 polio vaccination to the origin of human immunodeficiency virus". Phil. Trans. R. Soc. Lond. B, 2001; 356, 815-823, see p. 816.] This method of making new vaccine was not, as far as I know, adopted by other OPV producers, and would certainly not be allowed today, since it might allow a contaminant in one vaccine pool to be passed on to future pools. Producing a new pool from a well-characterised seed lot is clearly a safer process.

[xlv] Henle, W., Henle G., and Deinhardt F., "Studies on Hepatitis", Annual Report to the Commission on Viral Infections of the Armed Forces Epidemiology Board, March 1958 -- February 1959, see p. 5.

[xlvi] Deinhardt spent most of his time working with tissue cultures; indeed, eleven of his first twelve published articles (from 1954-1958) mention this in the title. In her unpublished scientific memoir, Gertrude Henle relates how when she and Dr Deinhardt sought the help of one of the great acknowledged experts on tissue cultures, Wilton Earle of the NIH, they were told that "three years of intensive training in his laboratory would be required. When [Dr Henle] pointed out that we were virologists who wanted to use the cultures merely as a tool·he threw up his hands in disgust. Yet we learned enough during the visit to start out on our own, an ineptly as it was initially."

[xlvii] This suggests that there may not have been any trypsin available in Stanleyville at this time, because previous experiments by Joseph Melnick, which were later promoted and advertised by Andrew Payne of the WHO, had demonstrated that the best method of transporting kidneys from a distant destination overseas (eg Bombay) was to trypsinise them before dispatch. [River, p. 388.]

[xlviii] This tissue culture of chimpanzee kidney cells and chimpanzee serum was of course different from the classic tissue culture of the fifties, which typically employed monkey kidneys (usually from rhesus or cynomolgus macaques), and foetal calf serum. The latter was expensive to buy, and would also have been impractical to make in Stanleyville, not least because of the shortage of cows in this "island in the rain forest". Besides, if serum from the same species which had provided the cells was available, it made sense to use it.

[xlix] Osterrieth, P.M., "Vaccine could not have been prepared in Stanleyville"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 839.

[l] Henle G., personal communication, 1993. The Armed Forces Epidemiology Board reports for 1957-8 and 1958-9 make it clear that four shipments of chimpanzee kidneys took place during 1958, which are presumably the ones dispatched by Deinhardt between February and April of that year. Two further chimp kidney shipments were sent later, presumably by Osterrieth. [See: Deinhardt F., Courtois G., Dherte P., Osterrieth P., Ninane G., Henle G. and Henle W.; "Studies of liver function tests in chimpanzees after inoculation with human infectious hepatitis virus"; Am. J. Hyg.; 1962; 75; 311-321.] Dr Henle added that Dr Koprowski had helped set up Deinhardtās visit. This further supports the possibility that Deinhardt might have agreed to deliver a sample of the new CHAT pool to Stanleyville, as a "gracious favour" to Koprowski.

[li] Although this conflicts with Osterrieth's statement to Plotkin that, for the few cultures he made in Stanleyville, "trypsin was uniformly used to disperse the cells from tissue", it ties in nicely with the later statement from Osterrieth's own article, in which he says that after his return to Africa in February 1958, "several months were required before I could attempt cell cultures using trypsinisation". Perhaps several months were not required to make cell cultures without trypsinisation.

[lii] From three different sources, it is known that Osterrieth, Osterrieth's assistant and Deinhardt were all present at this particular vaccination.

[liii] See: Melnick, J.L., "Tissue culture methods for the cultivation of poliomyelitis and other viruses"; in Diagnostic Procedures for Virus and Rickettsial Diseases; NYC: American Public Health Association; 1956); 97-151. Joseph Melnickās long article on tissue culture work during the 50s was treated by a bible by many of his contemporaries. In it, Melnick stated that when using the Maitland technique for making suspended cell cultures, a new culture needed to be prepared every two to four weeks. This raises the possibility that a fresh chimp cell culture might have been required virtually every time a new vaccine request came in to the Stanleyville lab.

[liv] Some may insist that no vaccine would have been tried on humans unless extensive safety tests had first been conducted. But in fact, both vaccines and chimps had already been tested. Safety testing of the CHAT poliovirus pool being used by January 1958, 10A-11, had already been carried out on both animals and human volunteers (the Clinton infants). Furthermore, we know that sera from the Lindi chimps had also been tested for major pathogens like simian B, tuberculosis and Coxsackie B, by Koprowski, Courtois, Deinhardt and Werner Henle. (River, p. 718). Of course, it was impossible to test the chimps for then-unknown pathogens, like SIV.

[lv] In November 1992, I went to interview Gaston Ninane, who was Osterrieth's colleague at the medical lab, and its director from October 1959 onwards. Some two hours into the interview I began asking him about how CHAT had been made, and Ninane told me three times in five minutes that the vaccine had been grown in chimpanzee kidney cells. Then, after referring to an article about the origin of AIDS in the Lancet (which identified the likely precursor host as the chimpanzee), he retracted, and said he had meant to say monkey kidney cells. In that he seemed genuinely confused, and had been speaking English for my benefit, I felt I had no choice but to believe him. [River, pp. 276-277.] And again, in early 2001, I interviewed one of the senior Belgian officials who had been responsible for vaccinations in the Congo. When asked what the chimps at Lindi had been used for, his immediate answer was for "the preparation of the vaccine". Later, he added that the chimps had been used to demonstrate the safety of the vaccine.

[lvi] Is there anywhere other than Stanleyville where an African-made version of CHAT might have been fed to humans? One strong possibility is at the mass field trial in the Ruzizi Valley (in eastern Congo and western Burundi), which involved vaccinating some 215,000 persons between February 24 and April 10, 1958. Two American doctors, Flack and Jervis, flew through Stanleyville on February 20, and briefly visited the medical lab, before flying on to Bujumbura. If they had been carrying a supply of vaccine with them from the US (which has never been confirmed), the vaccine might have deteriorated, because the flight from New York had been delayed by bad weather and the journey had taken three days instead of the normal two. (After three days, it is very possible that the ice in an insulated box would have melted, thus dramatically reducing the titre and efficacy of any vaccine stored therein.) Whatever, by March 4, Dr Ninane was apparently telegramming Koprowski in the US, urgently requesting more vaccine for the mass trial. [Plotkin S.A. "Untruths and Consequences: the false hypothesis linking CHAT type 1 polio vaccination to the origin of human immunodeficiency virus". Phil. Trans. R. Soc. Lond. B, 2001; 356, 815-823, see p. 818.] So whether or not it was initially intended to use locally-made vaccine in the Ruzizi trial, it might have happened by default.

[lvii] Stanleyville and Uvira in the Congo; Bujumbura, Rumonge and Kihanga in Burundi. Apart from Stanleyville (with a 1958 population of about 60,000) and Bujumbura (about 15,000), the other three were small towns or villages -- probably with populations of less than 5,000. For these places to be among the first sites where HIV emerged is therefore, at the least, a remarkable coincidence.

[lviii] Osterrieth's assistant recalls him making polio vaccine throughout the 1958-1960 period, up to independence on June 30, 1960, so it may be that many more vaccine trials (including some of those staged in the capital, Leopoldville, now Kinshasa) involved vaccine made in Stanleyville. But without further information about what happened in the Stanleyville virology lab, it is impossible to know for how long chimpanzee cell culture might have been used to make the vaccine, after the February to April 1958 period when we know that this material was present and available. (Perhaps, for instance, it was superceded by trypsinised rhesus macaque kidney tissue culture a few months later.) Of course, from the perspective of the OPV hypothesis, it requires just one trial (like that at Stanleyville military camp) to have employed vaccine made in chimp cells, for the principle to be established. Indeed, if the vaccines fed at the camp were infected with SIV, the impact could have been far-reaching, because these soldiers, after completing their service, dispersed to homes situated all over the colony.

[lix] Before publication, Koprowski's lawyers were in frequent contact with my US publishers, urging them to send them copies of any passages relating to Koprowski. My publishers declined, on the grounds that the book had already been very carefully vetted. Since publication, lawyers representing Dr Koprowski have approached at least one scientific journal, enquiring of an editor there whether she was aware that this topic had been the subject of litigation in the past. I myself have received several letters from lawyers representing both Koprowski and Plotkin (and from Koprowski himself), threatening me with legal action. There were other pressures too, from non-legal sources. Early in 2000, senior American scientists tried to persuade the organisers of the Royal Society conference to cancel the meeting. In the end, the London conference went ahead, but only after significant changes had been made to the programme which gave the meeting an inbuilt bias against the OPV theory. Then, in the closing speech at the meeting, Robin Weiss devoted a lengthy section to a criticism of the OPV theory, acknowledging that his words reflected "my personal biased view·[my] plain personal prejudice". This included a significant statement about the theory which was apparently addressed directly to me: "If you still believe it happened, then you are accusing us of being liars, and that is ineluctable." To my mind, the inclusion of the word "us" was significant. [Brian Martin currently has an article submitted on the political aspects of the conference, entitled: "The Politics of a Scientific Meeting: the Origin-of-AIDS Debate at the Royal Society".] More recently, Professor Weiss has been in contact with the organisers of this conference (at Lincei), and apparently sought (and failed) to persuade them to drop me from the list of invited speakers -- because, he claimed, the OPV theory had already been disproved. Later, he apparently suggested that he or a colleague could deliver a closing summary -- an offer which was also declined. I thank those responsible at the Lincei academy for their principled stance in allowing all sides of the argument to be heard.

[lx] Time for a brief digression about certain members of the opposition. Stanley Plotkin appears more and more like a paid-up member of the John P. Moore school of scientific critique, which seems to be based on hyperbole and attempts to discredit. (For examples, see Moore's comments in a letter to the Daily Telegraph, March 20, 2000, ["Why Aids scientists will snub the Royal Society"] and on the Amazon web-site for The River). Plotkin ends a recent article in Clinical Infectious Diseases ["CHAT Oral Polio Vaccine Was Not the Source of Human Immunodeficiency Virus Type 1 Group M for Humans"; CID, 2001, 32, 1068-84] by thanking Moore "for lending me some of his courage to face defamatory accusations". I find this intriguing, for my own experiences with Dr Moore are rather different. I find that whereas he likes to hand out trenchant criticism, he is not so good at taking it when the tables are turned. For instance, in June 2000, Moore sent me two unsolicited page-long e-mails of abuse (the second of them copied to three scientists) because, in the revised postscript to The River (pp. 851-852, 2000 paperback edition), I had dared to describe his Nature review of the book as "scurrilous". I ignored the e-mails, but later, during an interview, showed them to a journalist who asked me what sorts of opposition I had encountered. He subsequently quoted a couple of Moore's more pungent comments (such as his reference to me as "a tenth-rate journalist"), only to receive an incandescent call from Moore a day or two later, complaining that he had been quoted without permission. (It did not seem to have occurred to the good doctor that if he didnāt want his tirades to be quoted, he should consider not sending them in the first place.) On another occasion, Moore was dispatching an e-mail note to Beatrice Hahn, but somehow addressed a copy to the wrong person. Within hours, his message to "Bea" was circulating on the Net, with its reassurance to her that "you came across better than you think" in a Scotsman article in which she had referred to The River as "a piece of shit". (Nicoll, R., "AIDS -- A Man-Made Epidemic?"; The Scotsman magazine; June 24, 2000; 16-21.] Similarly, early in 2000, Moore wrote a series of angry and abusive letters to those organising the Royal Society meeting, and did his best to dissuade others from attending. In the Daily Telegraph, he made much of the fact that he himself would not be coming because he had better things to do, but neglected to say that he had not actually been invited as a full speaker. What all this confirms is that Moore has an agenda. Like his friends Steve Wolinsky and the journalist, Laurie Garrett, he is close to various members of the anti-OPV lobby, and seems to act as a sort of hands-on PR consultant on their behalf. Whether influenced by Moore or not, Stanley Plotkin is himself nowadays employing an increasing level of hyperbole and abuse. His persistent and unjustified attacks have persuaded me that it is now time to set the record straight on a number of issues. I have therefore decided to ask the editors of Clinical Infectious Diseases, who published Plotkin's recent text as an "invited article", whether they are willing to give me a chance to respond, on the grounds that I believe Plotkin's piece to have contained many examples of error, inaccuracy, misrepresentation, exaggeration and spin. [Some of these bordered on the comical. On pages 1077 and 1078, Plotkin made two references to "the Kikwit cases" (a couple who contracted AIDS in 1987 and 1988), claiming they had been "added to the map" of AIDS cases up to 1980 which appeared in The River, and that he had removed them in his analysis. Neither my map (River, p. 745), nor the text which accompanies that map (pp. 741-748), makes any reference to these two cases. The only place where these two cases appeared on a map of AIDS cases up to 1980 was on one of the two versions of my map which Dr Plotkin's team was circulating with copies of his speech at the Royal Society conference. Is this an example of his new-found courage -- to change one of my maps inappropriately, and without permission, and then accuse me of having done so?) But as I say, I would like to be offered a chance to respond to Dr Plotkin's claims. Then, perhaps, I could stop writing such interminable footnotes!

[lxi] Whether any samples of this vaccine still remain (perhaps in a freezer somewhere in the U.S. or Belgium), or (if they do) whether they would ever be released for independent analysis, are moot points.

[lxii] Beale J. and Horaud F., "Polio vaccine and retroviruses"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 841-843.

[lxiii] This is despite the valiant efforts of Bill Hamilton, whose chimpanzee stool samples are now, I hear, being reexamined by Dr Hahn. See: Sharp P.M., Bailes E., Chaudhuri R.R., Rodenburg C.M., Santiago M.O., and Hahn B.H., "The origins of acquired immune deficiency viruses: where and when?"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 867-876.

[lxiv] Wherever the Coquilhatville/Mbandaka chimp came from, it had to be have been from somewhere on the north bank of the Congo river, and both types of chimpanzee (Hahnās west central African Pan troglodytes troglodytes, and the central African Pan troglodytes schweinfurthii) are to be found on the north bank facing Coquilhatville district. The fact that at least one chimp came from Coquilhatville is, I believe, more significant than Ghislain Courtoisās 1967 claim that he had only worked with schweinfurthii, for it is extremely unlikely that Courtois would have distinguished between the two subspecies on the basis of physical differences. (In any case, mitochondrial evidence has called into question the legitimacy of the genetic distinction between the two subspecies, which may perhaps, in future, be amalgamated into one. See Gagneux P., Gonder M.K., Goldberg T.L., and Morin P.A., "Gene flow in wild chimpanzee populations: what genetic data tell us about chimpanzee movement over space and time"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 889-897.) The Mbandaka chimp arrived at Lindi in April 1957, and was still alive two years later. One chimp from Stanleyville zoo arrived in June 1957, and died in February 1958, with different organs being sectioned for virological analysis; the second chimp from that zoo arrived in February 1958. Since these three chimps come from a subset of 54 for which we have some details courtesy of Fritz Deinhardtās databook, it may be that some of the other 550-odd Lindi chimps also came from Pan troglodytes troglodytes territory.

[lxv] There is also another reason. As Bill Hamilton suggested, it may still emerge that a close ancestor to HIV-1 Group M is to be found in the pygmy chimp, Pan paniscus, more than 80 of which were co-caged with the common chimps at Lindi. To date, very few Pan paniscus have been sampled for SIV -- and sadly, Billās own efforts to obtain such samples appear to have been unsuccessful.

[lxvi] Data obtained by dividing AIDS (or HIV-1M) cases from Kinshasa by African AIDS cases (or HIV-1M infections) which are associated with a specific town. 13 of 31 and 21 of 47, respectively.

[lxvii] See preceding note. 21 of 31 and 40 of 47, respectively. In addition, it is worth adding that every instance of Group M infection in Africa through 1980 comes from within 225 kilometres of a CHAT vaccination site.

[lxviii] Sharp P.M., Bailes E., Chaudhuri R.R., Rodenburg C.M., Santiago M.O., and Hahn B.H., "The origins of acquired immune deficiency viruses: where and when?"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 867-876. Yusim K., Peeters M., Pybus O.G., Bhattacharya T., Delaporte E., Mulanga C., Muldoon M., Theiler J and Korber B., "Using human immunodeficiency virus type 1 sequences to infer historical features of the acquired immune deficiency syndrome epidemic and human immunodeficiency virus evolution"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 855-866. Salemi M., Strimmer K., Hall W.W., Duffy M., Delaporte E., Mboup S., Peeters M., and Vandamme A-M, "Dating the common ancestor of SIVcpz and HIV-1 Group M and the origin of HIV-1 subtypes by using a new method to uncover clock-like molecular evolution"; FASEB J.; 2000. The phylogenetic argument continues to be lauded in the press. See, for instance, Gina Kolata, "The Genesis of an Epidemic: Humans, Chimps and a Virus", New York Times, September 4, 2001, which claims that these doctors have "unravel[led] the mystery of the origin of the epidemic".

[lxix] See, for instance, Burr T., Hyman J.M., and Myers G., "The origin of acquired immune deficiency syndrome: Darwinian or Lamarkian?"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 877-888.

[lxx] In his Royal Society article, Paul Sharp pronounced, rather condescendingly, that my interpretation of the impact that recombination might have on dating was "strange", because "it is clear that recombination would make the date of the common ancestor seem more recent". [Sharp P.M., Bailes E., Chaudhuri R.R., Rodenburg C.M., Santiago M.O., and Hahn B.H., "The origins of acquired immune deficiency viruses: where and when?"; Phil. Trans. R. Soc. Lond. B; 2001; 356; 867-876.] But what is Sharpās evidence for this claim? An increasing number of articles are being published which conclude that he is wrong in this assumption, and that ignoring recombination can lead to either under-estimation or over-estimation of the MRCA. See, for instance, recent articles by Michael Worobey and Mikkel Schierup. One sceptical geneticist states that all the work done on dating the Group M epidemic up to now has been a "dogās breakfast". Another points out that there are questions about the accuracy of the fragmentary ZR59 sequence, which allegedly originates from Leopoldville/Kinshasa in 1959. [Zhu T., Korber B.T., Nahmias A.J., Hooper E., Sharp P.M., and Ho D.D., "An African HIV-1 Sequence from 1959 and Implications for the origin of the Epidemic"; Nature; 1998; 391; 594-597.] The short ZR59 sequence is used by some of the phylogeneticists as a check on the accuracy of their calculations. However, I hear from "inside sources" that the scientist who analysed ZR59 "was having a most difficult time with the sequence". My own researches reveal that there are genuine doubts about the provenance of the ZR59 sample, which may not originate from 1959 after all -- but rather from 1960 or 1961. (More details on this will appear in future.) The aforementioned sceptics about phylogenetic dating are not alone. Few, however, are willing to go on the record, perhaps because this has become such a controversial issue that many feel it unwise to be seen to be rocking the boat.

[lxxi] One other argument against the OPV theory is that the minor outbreaks of HIV infection (caused by HIV-1 Group O and Group N, and by HIV-2) appear to be caused by "natural transfer". Yet this is not a safe assumption. As I point out in the postscript to the 2000 paperback edition of The River (pp. 827-835 and 852-858), experimental French polio vaccines were administered in French West Africa and French Equatorial Africa (which embrace the hubs of the three minor HIV outbreaks) in the late 50s, a period when French researchers were working with both chimpanzees and sooty mangabeys, the hosts to the presumed ancestors of HIV-1 and HIV-2.

[lxxii] In the case of Africaās human population, approximately one million "volunteers" (who were not volunteers at all; see River, pp. 733-736) were vaccinated with CHAT, and yet there is apparently no longer any sample of the material they were vaccinated with, or any protocol accurately describing how that vaccine was prepared. In the case of its primate population, it seems that some 600 chimpanzees were sacrificed, and yet apparently those responsible for the research have kept no relevant records or biomedical samples. (The sole exception was the databook belonging to a man who visited Lindi camp for three months in 1958, Dr Friedrich Deinhardt.)

[lxxiii] This slow and painstaking search for the truth is actually the antithesis of the approach which Dr Koprowski claims I have adopted -- namely to search for facts to fit a preordained theory. [See: Koprowski H., "Hypotheses and facts"; Phil Trans. R. Soc. Lond. B; 2001; 356; 831-834. For my response; see Brian Martinās web-site on the origins debate, at http://www.uow.edu.au/arts/sts/bmartin/dissent/documents/AIDS/.] But to summarise, I have always sought to play devilās advocate with seemingly supportive information, seeking first to test and disprove it, rather than the opposite. My rejection of Dr Ninaneās thrice-given 1992 admission about the use of chimp kidneys in CHAT [River, pp 276-277] is an example of this, but the book contains others too.