Posing the Challenge
In many respects, the concerns Duesberg expressed in his article in Cancer Research , published in March 1987, were an extension of those he had voiced earlier. Entitled "Retroviruses as Carcinogens and Pathogens: Expectations and Reality," this sixteen-page review article with 278 references presented no original research but continued the argument that Duesberg had been trying to put forward: that retroviruses are simply not "the vessels of evil they have been labeled to be." In recent years, the general hypothesis that viruses were linked to cancer had been gaining ground, in part because many viruses (both retroviruses and ordinary DNA viruses) had been isolated from tumors and leukemias, particularly in animals. Duesberg pointed out, however, that many of these same viruses "were subsequently found to be widespread in healthy animals and humans." In his view, only a specific subset of these viruses were actually oncogenic (cancer-causing): those containing a class of genes called onc genes. Retroviruses lacking these onc genes, according to Duesberg, were harmless and ubiquitous; they could "coexist with their hosts without causing any pathogenic symptoms."
Without question, had Duesberg stopped there his article would have been ignored by everyone outside of a narrow specialist community. But Duesberg had another point to make, one that would occupy the final third of the article. The scientist later recalled: "As I was writing … AIDS just sort of literally exploded into the news media, and an article on retroviruses not at least taking a position [on] AIDS would have been rather incomplete. …" From Duesberg's perspective, the identification of the HIV retrovirus as the causal agent in AIDS was highly problematic. First, he pointed to the considerable disparity between the number of people estimated to be infected with HIV and the number of people who actually had AIDS. In the United States, where one to two million people were believed to be HIV positive, the annual incidence of AIDS among the virus-infected groups was only 0.3 percent. In Haiti and Africa, where estimates of infection ran even higher, the annual incidence was estimated at less than 0.01 percent. Since the introduction of the hypothesized agent so rarely appeared to cause disease, Duesberg claimed that Koch's third postulate had not been satisfied.
Second, Duesberg argued that it was implausible that a retrovirus would cause illness years after infection. He noted that many people
infected with HIV report having a brief, mononucleosis-like illness a few weeks after infection, and that this is what might reasonably be expected from a retrovirus. By contrast, the claim that HIV also caused AIDS some years later was hard to reconcile with the claim that HIV directly killed T cells: "We are faced with two bizarre options: Either 5 year old T cells die 5 years after infection or the offspring of originally infected T cells die in their 50th generation, assuming a generation time of one month for an average T cell." Furthermore, Duesberg noted that, in a study published in 1986 and conducted by Gallo and his associates, viral RNA was detected in only one of every ten thousand to one hundred thousand T cells in infected persons. In Duesberg's view, it was absurd to claim that a virus expressing itself in so few cells could be causing so much damage, since the body is constantly manufacturing new T cells. Even if the virus were to kill every ten-thousandth T cell every twenty-four hours, "it would hardly ever match or beat the natural rate of T-cell regeneration." Finally, Duesberg argued that there was no "simian model" for AIDS as required by a strict interpretation of Koch's postulates. Studies of chimpanzees and monkeys deliberately infected with HIV showed that these primates failed to develop a condition like AIDS (although such primates did develop viral antibodies, along with a mononucleosis syndrome similar to that in humans, shortly after infection).
What, then, did it mean to test HIV antibody positive? For Duesberg, it meant that one was protected against the effects of HIV: The purpose of antibodies is precisely to protect the body against the spread and expression of a pathogen. Having antibodies to HIV was therefore like being vaccinated against the virus. Until the immune system had created these antibodies, the person infected with HIV might suffer from the mononucleosis syndrome; but once the person tested positive for antibodies (normally within weeks after infection), he or she was safe—at least from HIV. HIV didn't harm its hosts; it was simply one of the many viral infections sustained by people with AIDS or at risk for AIDS, as was Epstein-Barr virus and CMV (found in 80 to 90 percent of them) and herpes (found in at least 75 percent). Perhaps AIDS was caused by one of these other infectious agents, perhaps it was caused by something other than a virus; Duesberg had no way of knowing. But HIV alone "is not sufficient to cause AIDS and … there is no evidence, besides its presence in a latent form, that it is necessary for AIDS."