Stellenbosch University, Boston University - School of Public Health, University of the Witwatersrand - Health Economics and Epidemiology Research Office, University of the Witwatersrand - Health Economics and Epidemiology Research Office, World Health Organization (WHO) - Department of Immunization, Vaccines and Biologicals (IVB), World Health Organization (WHO), World Health Organization (WHO) - World Health Organization for Africa, Independent, World Health Organization (WHO) - Global HIV, Hepatitis and STI Programme, University of Cape Town (UCT) - Centre of Infectious Disease Epidemiology and Research (CIDER) and World Health Organization (WHO) - Global HIV, Hepatitis and STI Programme