A Medical Accident?

Devastated by outbreaks of paralytic polio, the people of the Belgian Congo (now Zaire) had every reason to be thankful in 1957, when they became the first large group to receive an experimental polio vaccine. Ironically, the quest for deliverance from this ancient scourge may have made them unwitting participants in the birth of a new plague -- AIDS. That, at least, is the contention of a speculative but intriguing article in Rolling Stone.

The oral vaccine, developed by Dr. Hilary Koprowski of Philadelphia's Wistar Institute, was made from weakened polio viruses grown in a culture of monkey kidney cells. Several monkey viruses have been known to contaminate such cultures, though vaccine makers now take pains to weed them out. Extrapolating from a number of coincidences -- the testing of the vaccine in the very site where AIDS is thought to have begun; Koprowski's recollection that he cultured the virus in the tissue of green monkeys, a species that harbors a virus similar to HIV -- writer Tom Curtis hypothesizes that the vaccine was contaminated with a virus that evolved into the deadly HIV. From equatorial Africa, it spread worldwide.

There are problems with the theory. It is not clear that HIV can survive oral ingestion. Also, if the noxious seed was sown in the '50s, why didn't African doctors notice it sooner? Curtis offers possible explanations, but the clearest resolution would be to test the original vaccine stocks, still on ice at Wistar, for HIV-like viruses. Wistar officials last week said they would form a committee "to evaluate the Rolling Stone speculations." Meanwhile, there is no reason to worry about standard polio vaccines: they are rigorously screened for contamination.