Patient description: A 3-day-old Asian female infant presents with jaundice that started a day ago. She was born at 38w3d of gestation, after an uncomplicated pregnancy. The family history is unremarkable. The baby is breastfed. Vital signs are reported as: axillary temperature: 36.3°C, heart rate: 154 beats/min, respiratory rate: 37 breaths/min, and blood pressure: 65/33 mm Hg. Her weight is 3.2 kg, length is 53 cm, and head circumference 36 cm. Her sclera are yellow and her body is icteric. No murmurs or any other abnormalities are detected in the heart and lung auscultation. Her liver and spleen are normal on palpation. Laboratory results are as follows: Serum total bilirubin: 21.02 mg/dL Direct bilirubin of 2.04 mg/dL AST: 37 U/L ALT: 20 U/L GGT: 745 U/L Alkaline phosphatase: 531 U/L Creatinine: 0.3 mg/dL Urea: 29 mg/dL Na: 147 mEq/L K: 4.5 mEq/L CRP: 3 mg/L Complete blood cell count within the normal range. She is diagnosed with uncomplicated neonatal jaundice that may require phototherapy.

Clinical trial eligibility criteria: eligible ages (years): 0.0-999.0,  HIV Infections Maternal Mother is living with HIV and either i) known to have HIV diagnosis prior to labor (testing obtained and designated per local SOC in the medical record and either on or recently started CART prior to delivery) or ii) identified as having HIV diagnosis at the time of labor or in the immediate postpartum period. More information on this criterion can be found in the protocol Risk of mothers transmitting HIV to their infants Cohort 1 and Cohort 2 (RAL-naive): Mother living with HIV is at "high risk" of transmitting HIV to infant as evidenced by any of the following: Mother has not received any ARV therapy during the current pregnancy prior to the onset of labor and delivery; HIV RNA level greater than 1000 copies/mL within 4 weeks (28 days) prior to delivery; receipt of ARV for less than 4 weeks (28 days) before delivery; on ARVs for 4 weeks or longer but has not taken any ARV for more than 7 days prior to delivery; or mother has documented drug resistant virus to at least one class of ARV drugs Cohort 2 RAL-exposed: there was no requirement that the mother living with HIV is at "high-risk" of transmitting HIV to her infant Maternal written informed consent for study participation Maternal  Known maternal-fetal blood group incompatibility as evidenced by the presence of an unexpected clinically significant maternal red cell antibody that is known to be capable of causing hemolytic disease of the fetus/newborn Mother will be receiving RAL as part of her combination antiretroviral (cART) regimen after delivery and intending to breastfeed her infant For Cohort 1 and Cohort 2 RAL-naive groups Cohort 1 RAL-naive: Mother who received RAL prior to and through delivery unless last RAL dosing during prenatal period was >7 days prior to delivery Cohort 2 RAL-naive: Mother who received RAL prior to and through delivery Infant Age at enrollment (Note: The full-term infants were HIV-exposed and may have received standard of care ARV prophylaxis/treatment before enrollment) Cohort 1 and Cohort 2 RAL-naive: Aged 48 hours or less Cohort 2 RAL-exposed: Aged 60 hours or less Infant gestational age at birth at least 37 weeks No known severe congenital malformation or other medical condition not compatible with life or that would interfere with study participation or interpretation, as judged by the examining clinician