PIP: The development and testing of safe, effective, and affordable microbicidal products for women at risk of human immunodeficiency virus (HIV) raise complex scientific, ethical, and political issues. Ideal would by range of products (gels, foams, suppositories) that protect against HIV and other sexually transmitted diseases without impairing conception. This, in turn, requires the development of vaginal compounds that prevent the attachment of HIV-infected lymphocytes to epithelial surfaces, the secretion of virus from these cells, or the uptake of the virus by the mucosal epithelium with minimal cell membrane disruption. Problematic would be the design of a Phase III effectiveness trail that distributes the burdens and benefits of research equitably and provides controls with an alternate means of protection against HIV while maintaining scientific rigor. Since clinical trials call for a study population with a high seroincidence rate attributable primarily to the sexual transmission of HIV, prostitutes are the logical choice of subjects; sex workers are, however, the women most vulnerable to physical and economic exploitation. Women's input will be essential at each stage of development and testing, and such consultation can provide valuable feedback on method of application and timing of insertion. Finally, public-sector organizations must assume a leadership role in the coordination of the development of HIV prevention technologies.