Trial to Study the Effect of Dose of Herpes Simplex Virus-2 (HSV-2) Suppressive Therapy on HSV and HIV

We propose to conduct a randomized, open-label, cross-over study of 38 individuals who are HIV-1 seropositive and HSV-2 seropositive. Both men and women will be recruited for the study. Participants must not be on antiretroviral therapy and must not be planning to initiate antiretroviral therapy during the anticipated study period. Participants will be randomized 1:1 to receive acyclovir 400 mg twice daily or valacyclovir 1000 mg twice daily. After 12 weeks on the initial treatment, each participant will be crossed over to the alternative treatment arm for 12 weeks. The treatment periods will be separated by a 2-week washout period. During the first four weeks of each treatment period (i.e. weeks 1-4 and weeks 15-18), participants will provide self-collected genital swabs daily for HSV DNA quantification. Each week during the entire study period plasma samples will be collected from participants for HIV-1 RNA quantification. Open-label acyclovir and valacyclovir will be used for this trial, as the primary outcome measures (genital HSV and plasma HIV-1) are unlikely to be influenced by knowledge of treatment assignment. However, laboratory staff performing plasma HIV-1 and genital HSV measurements will not be aware of treatment assignment. Optional Sub-Study A: Sub-study A will be offered to study participants. The purpose of sub-study A is to measure the effect of valacyclovir twice daily on plasma HIV-1 replication.