1. A Division of the National Health Laboratory Service, Centre for Vaccines and Immunology, National Institute for Communicable Diseases, Johannesburg, South Africa
2. Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
3. Chemical Pathology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
4. Cochrane South Africa, South African Medical Research Council, Cape Town, South Africa