1. Uganda Virus Research Institute (UVRI), Uganda Research Unit on AIDS, Entebbe, Uganda.
2. Medical Research Council (MRC)/UVRI, Uganda Research Unit on AIDS, Entebbe, Uganda.
3. Virus Reference Department, Public Health England, London, United Kingdom.
4. Department of Infection and Immunity, University College London, London, United Kingdom.
5. MRC Clinical Trials Unit, University College London, London, United Kingdom.