U.S. researchers stung by claims of AIDS origin

PHILADELPHIA, Nov 8 (Reuters) - An eminent U.S. medical research centre will release lab specimens from a 1950s polio vaccine project in Africa in hopes of dispelling claims that its scientists inadvertently caused the AIDS epidemic, officials said on Monday.

For more than a decade, the Wistar Institute and two of its leading scientists have been dogged by speculation that the AIDS virus jumped from chimpanzees to humans through an oral polio vaccine given to more than one million people, mostly children, in central Africa.

The private, nonprofit institute said it would allow two independent labs to test material from the 1957-60 vaccine trials in hopes that this will end the controversy by showing no evidence of the chimpanzee form of the virus that causes AIDS, called SIV.

Scientists believe the AIDS epidemic, which has stricken 33 million people worldwide, began after SIV jumped the species barrier to human beings in western central Africa. The U.S. Centres for Disease Control says it probably occurred during the slaughter of chimpanzees as early as the 1930s.

Recently, however, the polio vaccine theory has been thrown back into the spotlight by a new book by British journalist Edward Hooper, whose research suggests that vaccine batches may been made from chimp kidneys and tainted with SIV.

Two Wistar scientists who led the polio research, former institute director Hilary Koprowski and his former deputy Stanley Plotkin, reject the suggestion.

"The idea is a house of cards built on circumstantial evidence, and whatever doesn't fit has been ignored. It's also, frankly, an attack on people's reputations, and I feel it has to be dealt with," said Plotkin, 67, who developed the modern rubella vaccine before leaving Wistar for France's Pasteur Merrieux Connaught.

Plotkin expects to choose the two labs that will conduct the tests and have the material with them by the end of this year.

"We just feel we can put that issue to rest if it's tested. Then ... we've done exactly what people feel would be necessary at least to relieve the tension over this issue," said Wistar Chief Administrator Clayton Buck.

In the late 1950s, the Wistar Institute was racing to develop an attenuated live polio vaccine that could be dispensed quickly to protect people from the crippling disease.

Koprowski, Plotkin and their Belgian colleagues developed an experimental vaccine, tested it in the United States and gave it orally to hundreds of thousands of children during trials in the then Belgian Congo, now the Democratic Republic of the Congo.

Hooper's 1,104-page book, "The River: A Journey to the Source of HIV and AIDS," published last September by Little, Brown & Co., contends that some of the children who received the vaccine could have been infected with the chimp virus.

Hooper did not return calls to his home in Britain.

Koprowski said chimpanzees were used only to test the vaccine and never to produce it. Instead, researchers made the vaccine with kidney tissues from Asian rhesus macaque monkeys, whose kidney cells do not support SIV or HIV.

"This book has only preconceptions. There are no facts," said Koprowski, now professor of microbiology and immunology at Thomas Jefferson University in Philadelphia.

The Wistar Institute faced similar assertions in 1992, when Rolling Stone magazine published an article on the polio-AIDS theory. At the time, the institute formed an outside panel of scientists who concluded the polio trials had not been responsible.

Three years later, Swedish scientists tested some of the vaccine used in Africa and found no evidence of SIV or HIV. Plotkin said the Swedes looked at only one of two lots involved in vaccine production and that new tests would encompass both.