IMPAACT P1115 will explore the effects of early intensive ART on achieving HIV remission (HIV RNA below the limit of detection of detection of the PCR assay) among infants infected with HIV in utero. Infants in this study will initiate ART within 48 hours of birth and will first be evaluated to determine whether HIV RNA can be detected in their blood while they are on ART. Upon reaching two years of age, infants with undetectable HIV RNA will be evaluated to determine if they meet study criteria to stop taking ART. Infants who meet these criteria will stop taking ART and will be monitored closely to determine whether HIV RNA remains undetectable while they are off ART. For any infant who stops ART and then has HIV RNA detected, ART will be re-started.