A randomized cross-over trial of herpes simplex virus type 2 (HSV-2)-suppressive therapy (valacyclovir, 500 mg twice daily, or placebo for 8 weeks, a 2-week washout period, then the alternative therapy for 8 weeks) was conducted among 20 Peruvian women coinfected with HSV-2 and human immunodeficiency virus type 1 (HIV-1) who were not on antiretroviral therapy. Plasma samples (obtained weekly) and endocervical swab specimens (obtained thrice weekly) were collected for HIV-1 RNA polymerase chain reaction. Plasma HIV-1 level was significantly lower during the valacyclovir arm, compared with the placebo arm (-0.26 log10 copies/mL, a 45% decrease [P < .001]), as was cervical HIV-1 level (-0.35 log10 copies/swab, a 55% decrease [P < .001]). Suppressive HSV-2 therapy has the potential to reduce HIV-1 infectiousness and slow HIV-1 disease progression.
Trial registration: ClinicalTrials.gov NCT00465205.