Circumcision Protects against AIDS
Clinical Trials Terminated Because of Positive Results
NIH has terminated clinical trials after circumcision was seen to protect against spread of AIDS. This outcome is related to the ethics of research on human subjects.
As reported today by the Associated Press and the New York Times, two AIDS clinical trials have been halted because of positive results; the trials were designed to test whether men who had been circumcised were less likely to contract AIDS virus than uncircumcised men. As the New York Times story discusses, one trial involved approximately 3000 men in Kenya and the other involved about 5000 men in Uganda. At the outset, none of the men tested positive for HIV infection. The researchers divided study subjects into circumcised and uncircumcised groups, gave them safe sex advice, and conducted regular follow up tests. When these tests were analyzed, the National Institute of Health stopped both trials because the number of new infections, among the circumcised men, was approximately half of the number of new infections among the uncircumcised men; among the Kenya group, 22 of the 1,393 circumcised men later tested positive for HIV whereas 47 of 1,391 uncircumcised men tested positive.
In terms of the ethics of clinical trials, the action by the NIH illustrates how the concept of equipoise (or uncertainty) functions in the decision of when to initiate, or terminate clinical trials. Ethically, clinical trials should only be initiated when there is sufficient scientific uncertainty between various interventions (e.g., circumcise or not) to justify conducting the trial. Because clinical trials are, by definition, experimental in nature, all of the participants are being subjected to a certain level of risk when they take part in the trial. From this empirical fact, it follows that:
- If there are concrete societal benefits that derive from testing the hypothesis under consideration, then the trial is, from a societal standpoint, justified.
- Once the data indicates, however, that there no longer is a state of uncertainty—either the intervention works or it doesn’t—then the trial has to be terminated.
- If the proposed intervention does not work, then there is no need to continue the trial because those receiving the experimental therapy are being subjected to unnecessary risk.
- If the intervention does work—as in this case in which circumcision does appear protective against HIV infection—then the trial must be terminated and all subjects in the study must be offered the option of having the beneficial intervention.
This logic was clearly being applied in the decisions regarding these clinical trials; as the Associated Press article reported, “The studies' uncircumcised men are being offered the chance to undergo the procedure.”
One of the most famous historical examples of unethical research on human subjects—also involving sexually transmitted disease--that continued long after drugs were available to treat the subjects was the Tuskegee Syphilis Study.
Historically, the results of this new research are interesting because it shows that an ancient practice with originally religious associations has now been shown (scientifically) to have a protective health effect in the 21st century. In other words, it illustrates that the domains of science and religion do not have to be in conflict—as they are often portrayed in debates, for example, about stem cell research—they can be complementary.
