Intrapartum and neonatal single-dose nevirapine compared with zidovudine for prevention of mother-to-child transmission of HIV-1 in Kampala, Uganda: 18-month follow up of the HIVNET 012 randomized trial

Providing antiretroviral therapy to human immunodeficiency virus type 1 (HIV-1)-infected women at the onset of labor could offer a relatively simple and affordable means of preventing vertical transmission. The HIVNET 012 study team reported, in 1999, that a single-dose intrapartum/neonatal regimen of nevirapine significantly lowered the risk of mother-child transmission by 47% compared with a brief regimen of zidovudine. The 496 infants had been followed up for 14 to 16 weeks. Data now are available for these infants up to age 18 months. Participating mothers had been assigned to receive either 200 mg nevirapine at the onset of labor, with 2 mg/kg for the infant within 72 hours after birth (regimen A), or 600 mg zidovudine at the onset of labor, followed by 300 mg every 3 hours until delivery and then 4 mg/kg orally twice a day for 7 days for the infant (regimen B). Testing for HIV-1 estimated HIV-1 RNA up to age 1 year and HIV-1 antibody at age 18 months. The estimated risk of HIV-1 transmission was 10.3% with zidovudine and 8.1% in the nevirapine group at birth; 20% and 11.8%, respectively, by age 6 to 8 weeks; 22.1% and 13.5% by age 14 to 16 weeks; and 25.8% and 15.7% by age 18 months. In all, nevirapine was associated with a 41% reduction in the relative risk of HIV-1 transmission at last follow up (95% confidence interval, 16-59%). Multivariate analysis showed that highly significant factors, besides the treatment effect, included the baseline maternal viral load and CD4 cell count. Adjusting for breastfeeding status did not alter the treatment effect. Serious adverse infant events in the first 2 months after birth occurred in approximately 10% of both treatment groups, and events also were comparably frequent at age 18 months. Intrapartum/neonatal nevirapine appears to be a simple, inexpensive, and well-tolerated regimen for significantly reducing perinatal transmission of HIV-1 in less developed countries.