The New York Times has thrown its weight behind growing calls for a serious scientific enquiry into the role of CHAT oral polio vaccine in the origins of the HIV epidemic in the 1950s.
The calls follow the publication of The River, an investigation by journalist Ed Hooper into allegations that an early oral polio vaccine used in the former Belgian Congo was contaminated with SIV and may have provided the route by which HIV entered the human population. Hooper argues that some batches of the vaccine may have been cultured in kidney cells from chimps infected with a variant of SIV, and that an alarming correlation exists between the places in which this vaccine was administered and the places in which the earliest cases of AIDS have been identified.
A leading virologist, Simon Wain-Hobson of the Pasteur Institute in Paris, praised Hooper's research in a review for the scientific journal Nature.
"To my knowledge, none has collated more data, explored more ramifications, or interviewed more of the few remaining protagonists than Ed Hooper" Wain-Hobson wrote. "The River cannot be seen merely as the latest reprinting of the idea, for it contains a vast amount of new research. Furthermore, some of the syntheses are as good as they come. I would give very high marks for his understanding of HIV virology and phylogenetics. Does he prove his case beyond a shadow of doubt? No, but then if Hooper could, this would be common knowledge. He does make a powerful case for soberly and squarely addressing the issue."
The seriousness of Hooper's investigation was also endorsed by another prominent virologist, Robin Weiss, writing in Science recently. Although sceptical of the polio vaccine theory, Weiss argues that there are important lessons to be learnt from The River about the care which is required in vaccine development for HIV.
Vaccine samples to be tested
In a response to recent pressure, the scientific institute which sponsored the polio vaccine research in question has announced that it will allow independent tests on samples of vaccine held in its archives to determine if they are contaminated. The Wistar Institute had previously refused to test the samples, but Edward Hooper is still not confident that the proposed tests will get to the bottom of the puzzle.
"It's unclear from their statement which samples they are offering to test, and what they are asking researchers to look for", he told aidsmap this week.
Professor Robin Weiss, in his review of The River, suggests that the Wistar Institute samples may be a red herring in any case. He cites Hooper's evidence that small-scale vaccine experiments by French and Portuguese scientists in West and Central Africa may also have been responsible for the dissemination of a primate virus into humans.
"To me, the possible use of small batches of experimental OPV made locally seems a more plausible source of contamination than the Wistar preparations", Weiss says.
Scientific conference demanded to examine origins of HIV epidemic
Edward Hooper is urging scientists to convene an international conference to examine the evidence, and he is also calling for a number of other investigations that could prove or disprove his hypothesis. These include:
- testing the CHAT vaccine samples for the mitochondrial DNA of primates to determine which primate kidney cells were used in the preparation of the vaccine.
- testing blood stored prior to 1959 in Central Africa, Belgium and other European countries to determine whether HIV-1 was present in humans before the first currently identified case
- an investigation of the procedure for making the CHAT vaccine. The vaccine preparation process has never been published in a scientific journal and scientists involved in the process have made contradictory statements. "It is inconceivable" says Hooper "that documentation does not exist somewhere".
- testing chimps for SIV in the areas originally used to gather animals for the vaccine studies; if the SIV genetic sequence is closer than the currently proposed `ancestor' sequences, this will be strong suggestive evidence too.
The River by Edward Hooper is published by Penguin Books (£25)