Billions of dollars of AIDS testing, treatment and government research funding are based on what most scientists consider a well-established fact--that AIDS is caused by HIV, the human immunodeficiency virus.
But for the past four years, a fringe group of scientists, including a former Medical School professor and a Nobel laureate, have been challenging the veracity of this basic supposition.
The Group for the Scientific Reappraisal of the HIV/AIDS Hypothesis, founded in 1991, says that there is no conclusive evidence that the HIV hypothesis holds true, in light of the failure so far to successfully treat AIDS and the slow manifestration of AIDS symptoms in patients.
The original HIV/AIDS link presented in 1984 was that HIV, a new mutant retrovirus, causes AIDS by killing CD4+ lympocytes. CD4+ lymphocytes, or helper T-cells, are white blood cells which organize the body's immune system to combat infection. The Center for Disease Control (CDC) incorporated this definition into its database and has used it ever since to diagnose AIDS.
But former Medical School professor Dr. Charles A. Thomas, a member of the reappraisal group and head of the Helicon Foundation, says he thinks the CDC's database definition is flawed. Thomas says the lack of a vaccine and an inability to identify antibodies to the virus shows a need to revise researchers' approach to combating the disease.
Most members of the scientific community, however, do not believe a reappraisal is necessary.
"My sense is that the scientific community thinks that the evidence is so overwhelming that it is confusing to non-experts why they have continued to pursue this hypothesis," says Professor of Chemistry Stuart L. Schreiber. "A large percent of the evidence makes it very clear that HIV causes AIDS. It is a waste of time and resources to reargue this."
Most of Harvard's leading AIDS scientists could not be reached for comment, including Professor of Microbiology and Molecular Genetics Dr. Ronald C. Desrosiers of the New England Regional Primate Center, Professor of Medicine Dr. Martin S. Hirsch at Mass General Hospital and Chair of the Harvard AIDS Institute Max E. Essex.
AIDS researcher and Professor of Pathology Dr. William Haseltine, who is often targeted for criticism by groups calling for a reappraisal of AIDS, declined to comment.
Thomas and other members of the reappraisal group say they believe HIV researchers are propagating the virus hypothesis to preserve their own funding.
"Nowhere has such a morally destructive scam by self-interested scientists been permitted," Thomas says. "$7.35 billion is being spent on AIDS research and education based on the HIV hypothesis. These dollars should not be taken from the taxpayers."
Thomas also charges the media with collaborating with the scientific establishment on this affair.
"The media wants to promote scare stories and do not want to tangle with homosexual advocacy groups," Thomas says. "HIV is not linked to AIDS."
Thomas says all the group wants is independent monitoring.
Not all of the members of the group are scientists. Tom Bethell, the Washington correspondent for the American Spectator, a conservative political publication, says people "should be willing to entertain theories other than HIV. They have placed all their eggs in one basket."
Bethell says he joined the group after hearing Duesberg lecture on the topic at the University of California at Berkeley.
Bethell says the resistance stems from the inability of government researchers to entertain conflicting hypotheses.
"Questioning the government does not extend to medical questions," Bethell says. "The source of money has a lot to do with the direction of research."
Bethell says the scientists more willing to support the group are the older, established ones who are sufficiently independent. "Understanding of science has become completely intertwined with such political considerations," Bethell says.
Another major tenet of the group is that AZT, the nucleoside analog drug commonly used to treat AIDS, is poisonous.
"AZT is a tremendously toxic substance that was used for cancer chemotherapy in the 1960s," Thomas says. "It was rejected because it was too toxic. Under a lot of pressure by AIDS groups it was put on the market."
Resistance to the group's ideas has been stiff.
Since 1991, the reappraisal group has tried to publish a letter in a scientific journal calling for a re-evaluation of AIDS research. A highly edited letter finally ran in the journal Science this past February, co-signed by 12 members of the group. The letter states, "Until we have a definition of AIDS independent of HIV, the supposed correlation of HIV and AIDS is a tautology."
Funding problems have also hit at least one of the group's members. The Crimson was told that Peter Duesberg, a professor of molecular biology at the University of California at Berkeley and a leading member of the group, recently lost grant money for his research.
Some scientists interviewed for this article say that Duesberg is a "crackpot," but did not wish to be identified for what one called "fear of retribution."
"Most scientists just do not understand how someone with this knowledge can take this attitude," one scientist says. "It is widely regarded as totally and utterly irresponsible."
It is unclear whether the loss of the grant is related to Duesberg's membership in the reappraisal group.
Duesberg could not be reached for comment, despite repeated messages left at his office. The HIV Virus
Thomas says he would like to see "just one paper that proports an assembly of evidence that HIV causes AIDS." But most established scientists say that while HIV's role in AIDS may have been unclear in 1991, a mountain of evidence since then has accumulated supporting the HIV hypothesis.
Schreiber says Duesberg was a respected virologist prior to this controversy.
"The best I can tell, I think Duesberg is genuinely concerned with this question," Schreiber says. "In the early days of this proposal, the evidence was less convincing, but during the period of time when he has been challenging the established AIDS theory, an enormous amount of evidence has arisen that supports the HIV theory."
According to Schreiber, Duesberg doesn't seem willing to address the new data supporting the HIV hypothesis. "He has refused invitations to comment on these new findings," Schreiber says.
Schreiber also says he is puzzled by the fact that Kary Mullis, the 1993 Nobel laureate in chemistry, is a member of the group. Schreiber says he suspects Mullis associates himself with the group to garner media attention.
Dr. Abul K. Abbas, professor of pathology at the Medical School, says, "Peter Duesberg has been supporting this line for sometime now. His proposal is controversial. The evidence in published work is overwhelming that HIV causes AIDS."
Abbas says, however, that HIV may not be the only factor involved in causing the disease.
Members of the Group for the Scientific Reappraisal of the HIV/AIDS Hypothesis call their cause the "story of the century," but Dr. Norman L. Letvin, associate professor of medicine at the Medical School, says "there is overwhelming evidence that HIV causes AIDS."
"There are a lot more useful ways to expend energy than calling for this reappraisal," Letvin adds.
But he tries to put the group in perspective. "The group's call for reappraisal may be a reflection of frustration from our inability to vaccinate AIDS."