University of the Witwatersrand - Perinatal HIV Research Unit, Johns Hopkins University - Bloomberg School of Public Health, University of the Witwatersrand - Reproductive Health and HIV Research Unit (RHRU), Vanderbilt University - Division of Infectious Diseases, Stellenbosch University, Gates Foundation, University of the Witwatersrand - Reproductive Health and HIV Research Unit (RHRU), affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, University of Cape Town (UCT) - Division of Chemical Pathology, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, University of the Witwatersrand - Perinatal HIV Research Unit and affiliation not provided to SSRN

Aurum Institute for Health Research, Aurum Institute for Health Research, University of Cape Town (UCT) - Desmond Tutu HIV Centre, University of Cape Town (UCT) - Department of Medicine, University of Cape Town (UCT) - Department of Medicine, Aurum Institute, Aurum Institute, Stellenbosch University, Interactive Research Development, Aurum Institute for Health Research, Aurum Institute for Health Research, University of Cape Town (UCT) - Department of Medicine and London School of Hygiene & Tropical Medicine - Faculty of Infectious and Tropical Diseases