Paul Redfern, The East African (Nairobi), September 21, 2000
© 2000 AllAfrica, Inc
Nairobi - The Two sides in the increasingly bitter row over the origin of Aids appeared to be as far apart as ever following a conference on September 11 at the Royal Society in London.
At the heart of the row is Edward Hooper's book The River, which claims that Aids arose as a result of an accident from polio vaccines tested in the then Belgian Congo in the late 1950s.
These vaccines, it is said, may have been made with tissue from chimpanzee kidneys, which it is alleged was accidentally contaminated with the chimpanzee precursor of the HIV virus.
The book says that the areas where the vaccine trials took place were the areas where the first HIV-positive infection rates were recorded (around Leopoldville and in Burundi).
Hooper's case in The River is strong and is backed by a small but growing band of the scientific community, who do not accept the "official" stance that the virus was caused by some kind of blood-related transfer from a chimp to a hunter, possibly a bite or a cut or by eating an infected chimp.
The 84-year old developer of the polio vaccine alleged to be the source of Aids, Professor Hilary Koprowski, was adamant that his polio research work had been falsely accused and said that Hooper's allegations were a "fantasy" which could endanger efforts to eradicate polio.
The original researchers say that only macaque monkeys, which do not harbour SIV, the chimp equivalent of HIV, were used in the preparation of the vaccine.
Detractors of Hooper's case have put forward four main counter-arguments, one of which has already been disproved. That is, that a man from Manchester in the UK might have died of Aids before the vaccine trials. Tests on his tissues now prove that he did not have HIV.
The second argument is that the genes of the modern strains of HIV suggest a family tree going back to possibly 1930. Even here, however, the argument could be offset by the possibility that the common viral ancestor could have been a chimp, not a human.
Thirdly, scientists have argued that urbanisation, sexual freedom and migration in the Belgian Congo at the time were sufficient to reawaken any small-scale infection caused by an infected chimp.
But the conference also heard how rare HIV is among the very people who should be most exposed if it comes from ape hunting: the pygmies.
Nor can scientists explain why the slave trade and the Belgian mining industries, which were just as socially disruptive as the changes during the late 1950s, did not "re-awaken" the ancestral virus.
Perhaps most damaging for Hooper's argument, however, is the fact that a set of samples from one of the relevant vaccine batches, which had been kept in a freezer in the Wistar Institute in Philadelphia, proved to be HIV negative and were not made from chimps.
Hooper, however, says he now has incontrovertible evidence that some of the vaccine batches were made in Africa and not the United States. It is not known if any of these survived.
In a leader article in the conservative Daily Telegraph newspaper, it was said that the evidence from Hooper's book is now such that it behoves the scientific community to prove that the 1957 and 1958 "Chat" oral polio vaccine trials did not bring about the advent of Aids.
"If Hooper is right, Western medicine will face the wrath of an entire continent ravaged by the worst pandemic since the Black Death," said the paper.