1 Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town , Cape Town , South Africa.
2 Division of Infectious Diseases and HIV Medicine, Department of Medicine, University of Cape Town , Cape Town , South Africa.
3 Faculty of Life Sciences, University College London , London , UK.
4 The Francis Crick Institute , London , UK.
5 Department of Medicine, Imperial College London , London , UK.