Scientists Reach no Conclusion on AIDS-Polio Vaccine Connection

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By Huntly Collins, The Philadelphia Inquirer, September 13, 2000

© 2000 Knight Ridder/Tribune News Service

LONDON _ The claim that the AIDS epidemic was set off by scientists at Philadelphia's Wistar Institute during polio vaccine tests in Africa in the 1950s suffered more blows here yesterday as the Royal Society of London concluded scientific debate on the topic.

"The theory has been seriously wounded _ maybe even mortally wounded _ by the last two days," said Preston Marx, a Tulane University virologist, reflecting the views of many of the 200 scientists from around the world attending the emotionally-charged meeting.

In the tradition of scientific meetings, no vote was taken to tally up opinion.

The symposium was convened to debate journalist Edward Hooper's claim that Wistar's polio vaccine had been contaminated with infected cells from chimpanzee kidneys. In this way, he argued in his book, "The River, the AIDS virus jumped from chimpanzees to humans.

The strongest evidence reported yesterday debunking Hooper's theory came from Paul M. Sharp, a virologist at the University of Nottingham in England.

He said studies based on genetic changes in the virus over time indicated that the particular group of viruses responsible for the human epidemic arose in people no later than 1940, 17 years before Koprowski's polio vaccine trials began.

The Nottingham findings are similar to research presented Monday by Los Alamos National Laboaratory in New Mexico and the Rega Institute for Medical Research in Belgium, both of which have put the date at around 1930.

The original transfer of the virus from chimps to people likely occurred centuries ago, scientists said, but those viruses didn't become deadly until 1930-1940.

At the end of the meeting, a number of top scientists who had been intrigued with Hooper's theory said they had now concluded it likely was not correct. "The evidence isn't there," said Robin Weiss, a virologist at University College of London and a syposium organizer.

Hooper left the meeting yesterday unshaken. "I certainly don't think the [oral polio vaccine] theory has been wounded, let alone mortally wounded," he said.

While rejecting Hooper's claims about the polio trials, Weiss said that Hooper had done a public service by calling attention to the potential dangers of spreading harmful microbes through contaminated vaccines, protein products such as blood clotting factor and xenotransplantation, in which animal organs are implanted in people.

"Biologicals have a danger and it's our business in public health to try and minimize the danger," Weiss said.

Hooper's ideas have been given a favorable ride in the British press, where mad cow disease has heightened public fears about animal diseases jumping to humans.

The prevailing theory of the origin of AIDS is that a hunter, likely in west-central Africa, cut himself as he butchered a chimp for meat, became infected with the chimp version of the AIDS virus, and then passed it on to others through sex.

A variation on that theory was presented yesterday by Marx of Tulane. He suggested that once the virus got into people, its spread was fueled by widespread re-use of contaminated syringes. During the 1950s, there was a marked increase such syringes in Africa to deliver antibiotics and vaccines for all types of diseases, Marx told the gathering yesterday.

Others questioned the hypothesis, noting that vaccines are given to children yet the first AIDS cases in Africa were among adults.

Stanley Plotkin, 68, former deputy director at Wistar and chief of infectious disease at Children's Hospital of Philadelphia, said he was hopeful that Hooper 's claims would finally be put to rest. "The facts do not in any way support the oral polio vaccine theory," he said.