University of Cape Town (UCT) - Department of Molecular and Cell Biology, The University of Western Australia - Division of Infection and Immunity, Biomedical Research and Training Institute, London School of Hygiene & Tropical Medicine - MRC Tropical Epidemiology Group (TEG), London School of Hygiene & Tropical Medicine, University of Cape Town (UCT) - Department of Medical Microbiology, University of Malawi - Malawi-Liverpool-Wellcome Trust Clinical Research Programme, London School of Hygiene & Tropical Medicine - Medical Research Council Unit: The Gambia, University of Malawi - Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Tromsø - Department of Community Medicine, London School of Hygiene & Tropical Medicine - Department of Clinical Research, University of Cape Town (UCT) - Department of Molecular and Cell Biology and Independent