Pregnancy in effectiveness trials of HIV prevention agents.

Despite remarkable progress over the past several decades in understanding the biology and epidemiology of the HIV pandemic the virus continues to spread relentlessly. Diverse prevention approaches are desperately needed to reverse this trend. For many women products that can be used without the cooperation of male partners are critical. Multiple such products are currently being tested in large-scale effectiveness trials and many more are in earlier stages of development. These products include physical and chemical barriers to viral entry vaginal pH buffers an antiherpes drug antiretroviral drugs and other agents. Some of these products may have contraceptive as well as anti-infective activity. The basic design of HIV prevention trials is standard: HIV-negative women at risk for HIV infection are randomly assigned to use either the study product or a placebo according to a specified schedule (e.g. daily or before each coital act) and then are followed to assess HIV incidence. Most HIV prevention trials are conducted in resource-poor settings in Africa and Asia where HIV incidence is high. (excerpt)