HSV-2 Suppression to Reduce Maternal HIV-1 RNA Levels During Pregnancy and Breastfeeding

Each year over 500,000 children become HIV-1-infected in sub-Saharan Africa after exposure to maternal virus in blood, genital secretions, and breast milk. Identifying feasible, safe, and affordable interventions that prevent mother-to-child transmission remains a priority for HIV-1 prevention research. Interventions to reduce breast milk HIV-1 transmission are lacking and most urgently needed.

We propose a randomized clinical trial to determine whether incorporating HSV-2 suppression with valacyclovir into standard prevention of mother-to-child HIV-1 transmission regimens will reduce plasma, cervical, and breast milk HIV-1 RNA levels and risk of transmission among HIV-1-infected and HSV-2-seropositive women. We plan to enroll a total of 148 HIV-1 and HSV-2 co-infected pregnant women with CD4>200 cells/μl who seek antenatal care prior to 32 weeks gestation at a clinic in Nairobi, Kenya. Women will be randomized to receive either valacyclovir suppressive therapy or placebo at 34 weeks gestation and mother-infant pairs will be followed for 12 months postpartum. Follow-up visits will be scheduled at 38 weeks gestation; birth; 2, 6, 10 and 14 weeks; and 6, 9, and 12 months postpartum. Maternal blood, genital, and breast milk specimens obtained at follow-up visits will be used to determine the effect of valacyclovir suppressive therapy on plasma and breast milk HIV-1 RNA levels. Infant filter paper specimens for HIV-1 DNA assays will be collected at birth; 2, 6, 10 and 14 weeks; and 6, 9, and 12 months in order to compare the proportion of infants acquiring HIV-1 by 12 months in the two study arms and determine the timing of HIV-1 infection. In addition, we will monitor maternal and infant renal function in preparation for a larger randomized clinical trial in Africa. The results of this study will help guide the design of a multi-site clinical trial with adequate power to determine the effect of HSV-2 suppression on vertical (MTCT) transmission of HIV-1 infection.