1 Botswana-UPenn Partnership, PO Box AC 157 ACH, Gaborone, Botswana; Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK. Electronic address: [email protected].
2 Institute of Infection and Immunity, St. George's University of London, London, UK.