A book published today presents research to suggest the vaccine was contaminated with a chimpanzee immunodeficiency virus which infected humans to cause the HIV epidemic.
Edward Hooper, author of The River (Penguin pounds 25), spent the past eight years investigating the theory which in 1992 was investigated by experts who rejected the idea as implausible. He claims to have found convincing support for the idea that the polio vaccine was contaminated and this led to a simian immunodeficiency virus jumping species from chimpanzee to humans.
The new evidence will put more pressure on the Wistar Institute in Philadelphia, which conducted the trials in Africa under the auspices of Hilary Koprowski, to release its stocks of polio vaccine which date back to the late 1950s.
Mr Hooper claims the Wistar used chimpanzee kidney tissue to culture the polio virus that formed the basis of the vaccine. The institute denies this, saying it used kidneys from Asian monkeys, which could not have been infected with an Aids-like virus.
However, Mr Hooper has traced the animal research camp at Lindi, in the then Belgian Congo, linked with the Wistar and found witnesses who claimed to remember chimps being used in scientific experiments.
Mr Hooper's exhaustively researched book points out:
n A high correlation between the use of the vaccine between 1957 and 1960 and subsequent outbreaks of HIV-1, the main Aids virus.
n The earliest confirmed case of HIV is from a stored tissue sample from Leopoldville, which is coincident in time and place with a major trial of the Wistar vaccine.
n Nobody has been able to confirm a case of HIV infection before 1957, the year when the Wistar vaccine trials started.
n Chimp kidneys were known to be a perfect culture medium for polio virus and would have been an obvious first choice for scientists interested in developing a vaccine.
n Dr Koprowski has given several different accounts of which monkey species was used in developing the polio vaccine and that the actual species used was never published at the time.
n The only close relative of HIV is the simian virus found in the common chimpanzee.
n An absence of documentation concerning the nature of the research work at the Lindi camp.
In response to suggestions made by Rolling Stone magazine in 1991 that the Wistar polio vaccine may have been responsible for Aids, the institute established a committee of independent experts to review the allegations. The committee reported in 1992, saying the chances of the vaccine being involved was remote. One of the principal arguments against its implication was the case of David Carr, a Manchester sailor who had apparently died of Aids in 1959.
The scientific committee said: "[Carr] had returned to England by the first half of 1957, before the Congo trial had begun. Therefore it can be stated with almost complete certainty that the large polio vaccine trial begun in 1957 in Congo was not the origin of Aids."
The Wistar Institute, which later forced Rolling Stone to publish a "clarification", issued its own press release in October 1992, stating: "The most conclusive evidence refuting the origin of Aids theory involves the earliest documented case of HIV-1 infection - a merchant marine [Carr] who was symptomatic in 1958 and died of Aids in 1959 in Manchester, England." The statement continued: "While this man travelled abroad to northern Africa beginning in 1955, he had returned to England by the first half of 1957, before the Congo trial was begun."
However, an investigation by The Independent in 1995 revealed that Carr, who had not travelled to Africa, had not been infected with HIV. The scientists who made the original claims subsequently retracted their research paper published in The Lancet in 1990.
Mr Hooper says in his book that the revelation undermined a major objection to the involvement of the polio vaccine trials in the origin of Aids.
There are nevertheless other problems with the Hooper hypothesis, which include:
n The fact that the polio vaccine was taken orally, which is a far more difficult route for HIV transmission, although not impossible.
n Objections to the theory by some HIV experts who believe the genetics of the virus indicate a passage from chimpanzee to humans some years earlier than the 1957 vaccine trials.
n Evidence that the second major type of Aids virus, HIV-2, has "naturally" transmitted from monkeys to human on several occasions, probably through the animals being hunted.
n Other areas of the world where the polio vaccine was used, such as Eastern Europe, did not experience a similar Aids epidemic.
However, Clayton Buck, deputy director of the Wistar, said last night that the institute is willing to consider the possibility of competent scientists testing old vaccine samples for signs of contamination. "I understand we have found some vials of polio virus [the vaccine] but we aren't sure if they are the original vials that were used in the trials."
The Wistar Institute has attempted to find an independent scientific agency which would agree to evaluate the possibility of testing the vaccine vials for simian immunodeficiency virus (SIV) but this has failed, Dr Buck said.
The institute said it has written to the World Health Organisation, the US National Institutes of Health and Centers for Disease Control in Atlanta, Georgia, offering the samples for testing. "We were unable to find anybody who would do this," he said. The tests are expensive and the scientists are unsure that they will be able to extract enough virus to produce any meaningful results, Dr Buck said. "We've been extremely proactive in finding that the vials are tested and have failed. He [Mr Hooper] would have to come up with some new and significantly strong argument [for this to go ahead]." However, with the latest book on the subject, there will be growing pressure on the Wistar to find an independent team to test the samples.
Origins: other theories about how Aids and HIV began
n HIV came from the blood of African chimpanzees killed by hunters, and crossed into humans earlier this century. Published in February, this theory has rapidly won approval from many scientists.
n HIV was developed as part of a biological warfare programme by a government - pick any of the US, USSR, South Africa or Israel. A popular idea with conspiracy theorists, but such development is utterly beyond scientific capability, even today.
n HIV is a mere bystander in Aids, which is caused by intravenous drug use and anal intercourse, helped by recreational drugs. This theory, taken up by Andrew Neil when editor of The Sunday Times, is disproved by people in the so-called "high risk groups" who do not get Aids: they have been found to have genetic resistance to HIV.
n HIV is a mutated form of swine fever, originating in Haiti. Disproven: HIV is not related to swine fever.Reuse content