Safety and Pharmacokinetics Study of PGT121.414.LS Alone and in Combination With VRC07-523LS in Infants Exposed to HIV-1

The purpose of this study is to evaluate the safety and pharmacokinetics (PK) of the potent, broadly neutralizing anti-HIV monoclonal antibodies (mAb) PGT121.414.LS alone and in combination with VRC07-523LS soon after birth in infants exposed to HIV-1.

Inclusion Criteria: * Birthing parent is of legal age or circumstance to provide independent informed consent and is willing and able to provide written informed consent for themselves and permission for their infant's participation in this study. * Birthing parent has confirmed HIV-1 infection based on positive test results from two samples collected from two separate blood collection tubes. * Infant was singleton or twin. * Infant's gestational age at birth was at least 36 weeks. * At birth, infant's weight was at least 2 kg. * At entry, infant is less than 72 hours of age and is anticipated to receive study product within 72 hours after birth. * At screening, infant has the following laboratory test results: * Hemoglobin, normal or grade 1 (≥13 g/dL or ≥8.05 mmol/L) * Platelets, normal or grade 1 (≥100,000 cells/mm3 or ≥100.000 x10\^9 cells/L) * Absolute neutrophil count (ANC), normal or grade 1 1. ≤24 hours old (≥4,000 cells/mm3 or ≥4.000 x10\^9 cells/L) 2. \>24 hours old (≥1,250 cells/mm3 or ≥1.250 x10\^9 cells/L) * Alanine transaminase (ALT), normal (\