This material is part of a collection on
Polio vaccines and the origin of AIDS
which in turn is part of the website on suppression of dissent.
Edward Hooper (LRB, 3 April) accuses me of having prepared CHAT, an oral polio vaccine, in chimpanzee cells contaminated with an HIV-related virus in February 1958. I have already categorically denied this in an article published in the Transactions of the Royal Society in 2001. The new evidence cited by Hooper consists of interviews with two persons said to be former technicians in my lab in Kisangani, Jacques Kanyama and Philippe Elebe. I remember Kanyama with affection, but he was a low-level employee with no scientific background who performed simple tasks and did not work with me on cell culture. Any judgment he could make more than forty years later is pure supposition. Elebe I do not know; he never worked with me and his testimony isn't of any value. CHAT polio vaccine was never produced in Kisangani - we had primitive equipment and no means of testing the purity, titre and safety of a viral vaccine. Moreover, in February 1958 I had just returned from a study visit to the United States, and could not, despite Hooper's allegations, easily have prepared a new pool of vaccine using the techniques which I had just learned.
University of Liège
Edward Hooper claims to have made a 'remarkable discovery' when interviewing technicians who said that they had worked in a laboratory in Kisangani which collaborated with me in research on poliomyelitis and its prevention. One of these technicians, Jacques Kanyama, provided Hooper with 'details' of his work during the polio trial. I do not recall any local technician who would have had knowledge of such 'facts' as those given to Hooper by Kanyama.
The 1958 report of the laboratory in which Paul Osterrieth worked recounts that cell cultures were achieved from baboon kidneys. No mention is made of chimpanzee cell culture or vaccine production. Also in print, however, is the fact that Osterrieth prepared six chimpanzee kidneys for dispatch to the United States for use in a project on viral hepatitis. In other words, when chimpanzees were used this was readily acknowledged.
Hooper repeats his assertion that early cases of Aids occurred where CHAT was used, but neglects to mention that most of his cases are unconfirmed and that there were many places where CHAT was administered without subsequent Aids and, conversely, where putative Aids occurred but CHAT vaccination did not.
University of Pennsylvania, Philadelphia
Edward Hooper dismisses the role of injections in the transmission of HIV on the grounds that 'all age groups and both sexes would have experienced comparable exposure to unsterile injections', while levels of infection vary dramatically according to age and sex. However, different groups receive injections from different sources. A survey conducted in Peshawar in 1995 showed that only 10 per cent of doctors there were paediatricians yet they were responsible for administering 90 cent of the injections given to young children. These injections would not have been contaminated with blood from adults with HIV. Most of those infected with Ebola in the outbreak in Yambuku in 1976 were pregnant women who had attended a special clinic to receive vitamin B injections. Some sex workers have prophylactic weekly injections, and STD clinics treat both sex workers and their clients. While HIV may be mainly transmitted sexually, unsterile injections may also play a very important role. There are more than sixteen billion injections given every year, almost all of them unsterile and most of them unnecessary and leading to the transmission of hepatitis, HIV and other bacteria, viruses and parasites.
University of Leeds
After nearly half a century, it is not surprising that Hilary Koprowski (Letters, 8 May) does not recall any local technician who would have had knowledge of the procedures for the preparation and administration of CHAT polio vaccine to 215,504 people in the Ruzizi Valley in the Congo early in 1958, or that he dismisses the account of one technician, Jacques Kanyama, as reported by Edward Hooper (LRB, 3 April). Few white researchers paid much attention to their African laboratory assistants, although Paul Osterrieth at least recalls Kanyama, a 'low-level employee', 'with affection'. Koprowski's memory has proved shaky on many crucial aspects of his early work on polio, both at the Wistar Institute in Philadelphia and in the Congo, and his rejection of Kanyama's account is hardly convincing. Osterrieth also dismisses Kanyama's recollections, describing them as 'pure supposition' and does not remember Philippe Elebe, the other technician Hooper spoke to.
It might jog their memories to look at the 'unknown African assistant' who figures in one of the photographs ('Staff of Stanleyville Medical Laboratory in mid-1958') in Hooper's book, The River, or at the photo of the 'two African assistants dismembering a dead chimp in the small "laboratory" at Camp Lindi in 1957'. These pictures make it clear that 'African assistants' were closely involved in many of the procedures carried out by the polio researchers, and that their testimony must be taken seriously.
Osterrieth also claims that, in Kisangani, 'we had . . . no means of testing the purity, titre and safety of a viral vaccine.' Yet his colleague Ghislane Courtois has specified the precise titre of the vaccine used in the Ruzizi mass trial, and that the vaccine was diluted sixty-fold with saline solution before feeding.
University of East Anglia
David Seddon (Letters, 5 June) wants to know how Ghislane Courtois knew the titre of the vaccine used in the Ruzizi mass vaccination trial in 1958. The titration was done in Philadelphia and Courtois was told to dilute the material sixty-fold in order to reach the desired dose. Paul Osterrieth (Letters, 8 May) is correct in stating that the titre could not be ascertained in Stanleyville.
Paul Osterrieth, Stanley Plotkin and Hilary Koprowski (Letters, 8 May), all of whom were intimately involved with the trials of the CHAT polio vaccine in Central Africa, continue to insist that this vaccine was never prepared in chimpanzee cells, and thus to deny any connection between the CHAT vaccination of about a million Africans in 1957-60 and the emergence of Aids in the same towns and villages between ten and twenty years later.
Osterrieth dismisses the memories of African technicians by saying that one was a 'low-level employee', while the testimony of the other 'isn't of any value'. He adds that he has already denied these claims in the Philosophical Transactions of the Royal Society. In that article, he contradicted some of his own previous statements (concerning, for instance, to which American institutions he sent chimpanzee kidneys), while remaining tight-lipped about other crucial details. He insisted that CHAT vaccine was never handled in his virology department at the Laboratoire Médical de Stanleyville (LMS), and that it 'could not have been prepared' there. Numerous witnesses from North America, Europe and Africa (not just the two I cited) disagree with Osterrieth on these two points, and some state that he prepared the vaccine himself.
But in which cells? Plotkin says that baboon kidneys were used for tissue culture, but the LMS annual reports record only a relatively tiny quantity of cells cultured from (at most) two baboons in 1958. Plotkin claims that 'when chimpanzees were used' for any work, this was 'readily acknowledged'. In the annual reports, however, references to the CHAT testing programme and the vaccination trials are obscure and minimal, and there is no information as to what activities necessitated the use of more than four hundred chimpanzees between 1956 and 1960. Several witnesses recall that Osterrieth handled tissue, cells and sera from chimpanzees throughout this period.
Finally, Plotkin complains that most of what I claim to be early Aids cases from Africa are unconfirmed. Nine of my 39 cases were confirmed serologically; the others were diagnosed as probable Aids cases by experienced Africa-based physicians. For both the full series and the subset of confirmed cases, the statistical correlations with the CHAT vaccination sites are highly significant.
Just as Stanley Plotkin's latest letter was being published in the LRB (10 July), I received a communication from him - a postcard with the caption 'Punishment of the Apple Stealers'. The photo showed one figure cracking another over the head with a club, and the message read: 'Dear Ed, Thinking of you. Stanley Plotkin.' There were, however, no answers to the key questions that have been put to him over the last nine years.
Plotkin's undocumented assertion that the titre of the oral polio vaccine (OPV) fed early in 1958 to 215,000 people in the Ruzizi Valley (between present-day Burundi and the Democratic Republic of Congo) was measured at the Wistar Institute in Philadelphia, and that the vaccine was then diluted 60-fold by Ghislain Courtois in Africa, contradicts the medical literature. Dr Courtois wrote that it was the specifically the 'mother-solution' of the vaccine that was stored in the freezer at Bujumbura that had a known titre (of about 15 million doses per millilitre), and that this vaccine was then diluted 60-fold to reach the accepted immunising titre of 250,000 doses. Virologists in the 1950s were well aware that OPV rapidly loses titre during transportation and when its temperature rises. So if Plotkin is correct when he says that the titration was done in Philadelphia, this would mean that the vaccine fed in Africa was of unknown titre.
Studies conducted in the 1950s by the National Institutes of Health revealed that the titre of OPVs fell between two-fold and eight-fold when moved between different labs in the United States, and an even greater loss of titre would be expected during the process of transporting OPV in an ice-box to Africa. After the further 60-fold dilution, such an under-strength vaccine would (according to the Wistar's own test data) have immunised only between 33 and 67 per cent of the target population, which would have rendered the world's first OPV mass-trial meaningless. If it did come from Philadelphia, why was the vaccine not titrated again in Africa, to allow its concentration to be properly established?