Randomized , open-label noninferiority trial conducted at Rahima Moosa Mother and Child Hospital , Johannesburg , South Africa , from June @ to December @ , enrolling @ HIV-infected children exposed to nevirapine for prevention of mother-to-child transmission who were aged @ years or older and had plasma HIV RNA of less than @ copies/mL during ritonavir-boosted lopinavir-based therapy ; @ were randomized and @ ( @ % ) were followed up to @ weeks after randomization .