Model systems for microbicide evaluations are inadequate. In vitro tests can provide support for drug efficacy but cannot reproduce the complex vaginal environment. The vaginas of experimental animals are poorly characterized and do not provide a sufficient representation of the human counterpart. In this project, we will modify our human xenograft system so that grafts of human vagina can be used for microbicide evaluation. The Specific Aims of the study are as follows: 1. Define the Composition of human Vaginal Xenografts 2. Determine Human Vaginal Xenografts Responsiveness to Sex Steroids 3. Test the Susceptibility of Human Vaginal Xenografts to Primary infections with Selected Pathogens 4. Determine the Effectiveness and Toxicity of Selected Microbicides on Pathogens in Human Vaginal Xenografts.