Did polio-vax monkey business start AIDS?

Call it the AIDS-origin theory that just won't die. The proposition that accidentally contaminated oral polio vaccines designed by Americans and administered experimentally to a million central Africans in the '50s may have started the pandemic has never precisely pleased the medical powers-that-be. Popularized in former BBC correspondent Edward Hooper's 1,100-page 1999 book, The River, the theory has been met with an indignant chorus of official debunking (see "The River Runs Through It," POZ, March 2000). "Polio Vaccines Exonerated," headlined a commentary in Nature last spring by Robin Weiss, a leading British AIDS virologist who cochaired a conference on the issue in fall 2000. "Some beautiful facts," Weiss wrote, "have destroyed an ugly theory."

The key "beautiful fact" was a finding that seven of the original frozen polio-vaccine samples showed evidence of neither HIV nor its chimp precursor, SIV. But Hooper argued that the samples came from the wrong vaccines -- not those administered in Africa. Now, Hooper offers further evidence that may breathe new life into his theory.

The River claims that circumstantial evidence pointed to chimpanzees -- the only species harboring SIV -- as the primate whose kidney tissue was used to grow the vax. Meantime, two of the main researchers have long insisted that they used only SIV-free Asian macaques. But during a recent trip to the Congo, Hooper interviewed the man who in 1958 assisted the director of a medical lab located near a camp housing hundreds of chimps used for polio research. "He volunteered the information that his boss prepared the polio vaccines in his own lab," Hooper says. The assistant also recalled administering the vaccine to some 3,000 Congolese. According to Hooper, several other recent interviews with former employees at the lab and camp, combined with the director's own previous statements, make a compelling case that chimps did indeed provide the tissue culture used for vaccine production. "This new information is important," Hooper says, "and not only with regard to the oral-polio-vaccine theory of how AIDS started. It also raises ethical questions about the ways the scientific establishment responds to theories it finds threatening and the ways trials are still conducted in the developing world." If ultimately proven, the vaccine-AIDS connection could offer powerful genetic clues in the hunt for vaccines and treatments, while suggesting heightened caution in using animal tissue for human medical interventions.

Yet, Weiss, ever the skeptic, insists that "Hooper has it wrong" in reporting interviewee recollections that contradict accounts by prestigious researchers. "I am not aware of any new information reported by Hooper," Weiss says, "only speculation that seems to grow wilder by the month."