Old polio vaccine free of HIV, SIV.

In a blow against a controversial theory about the origin of AIDS, tests have revealed that polio vaccine used more than 40 years ago in Africa wasn't tainted with any viruses or chimpanzee DNA. Thus, polio vaccinations are unlikely to have caused the initial transfer of human immunodeficiency virus (HIV) to people, says Claudio Basilico of New York University Medical Center.

Citing the work of three independent laboratories, Basilico announced the findings on Sept. 11 at a meeting of the Royal Society in London.

Journalist Edward Hooper suggested in his book The River (1999, Little, Brown and Co.) that scientists making polio vaccine used in the Belgian Congo in the 1950s may have cultured viruses for the vaccine in chimpanzee cells. That could have transferred an early strain of HIV or simian immunodeficiency virus (SIV) from chimpanzees to humans.

To investigate Hooper's hypothesis, laboratories in France, Germany, and the United States analyzed the old vaccine. None found HIV or SIV. They found DNA from Asian macaque monkeys, whose cells were used to make the vaccine, but no chimp DNA.

Eckard Wimmer, a virologist at the State University of New York at Stony Brook, says the finding will bolster people's confidence in immunizations in general. He acknowledges that Hooper did careful work that has made scientists more cautious about animal tissues they use in making vaccines. As for Hooper's assertion that polio vaccine might have launched the AIDS epidemic, Wimmer says, "the data just do not support him."