Breast milk HIV-1 suppression and decreased transmission: a randomized trial comparing HIVNET012 nevirapine versus short-course zidovudine

Abstract

Objective: To compare the effect of perinatal regimens of short-course nevirapine (HIVNET012)andzidovudine[Thai-CentersforDiseaseControlandPrevention(CDC) regimen] on breast milk viral shedding and perinatal transmission during the first 6 weeks postpartum in a randomized clinical trial. Design: Randomized clinical trial. Methods: Pregnant HIV-1 seropositive women in Nairobi, Kenya who planned to breastfeedwererandomizedtoHIVNET012orThai-CDCregimens.Twotofourbreast milk samples were collected each week between delivery and 6 weeks postpartum. Breast milk HIV-1 RNA was quantified using the Gen-Probe TMA assay. Infants were tested for HIV-1 DNA at birth and 6 weeks. Results: From March to October 2003, 76 women were enrolled and 795 breast milk samples were collected from 60 women who were randomized and followed after delivery. Between 3 and 21 days postpartum, nevirapine was associated with significantlygreatersuppressionofbreastmilklog10HIV-1RNA:days3to7(1.98versus2.42, P¼0.1); days 8 to 14 (1.78 versus 2.48, P¼0.005); days 15 to 21 (1.90 versus 2.97, P¼0.003). At 6 weeks, the HIV-1 perinatal transmission rate was significantly lower among those who took nevirapine than zidovudine (6.8% versus 30.3%, P¼0.02). Conclusions: Compared to a peripartum zidovudine regimen, nevirapine was significantly more likely to decrease HIV-1 RNA in breast milk during the first week and through the third week postpartum following single-dose administration, and corresponded with decreased transmission risk at 6 weeks. Sustained breast milk HIV-1 suppression may contribute to the ability of nevirapine to decrease perinatal transmission of HIV-1.