University of Washington, University of Washington, University of Alabama at Birmingham, University of Washington, Johns Hopkins University, University of the Witwatersrand - Reproductive Health and HIV Research Unit (RHRU), University of Cape Town (UCT), University of Cape Town (UCT), University of Cape Town (UCT), University of Cape Town (UCT), Qhakaza Mbokodo Research Clinic, Human Sciences Research Council (HSRC) - Centre for Community Based Research, Human Sciences Research Council (HSRC), Foundation for Professional Development, Wits Maternal Adolescent and Child Health Research, Setshaba Research Centre, Chris Hani Baragwanath Academic Hospital - Perinatal HIV Research Unit, University of the Witwatersrand, Klerksdorp-Tshepong Hospital Complex, Aurum Rustenburg Clinical Research Centre, Madibeng Centre for Research, South African Medical Research Council, Columbia University - ICAP, Kenya Medical Research Institute (KEMRI), Johns Hopkins Bloomberg School of Public Health, Malawi, UNC Global Projects, Bio Analytical Research Corporation South Africa (BARC SA), University of Washington, University of Washington, Fred Hutchinson Cancer Research Center and Independent