[1] London Sch Hyg & Trop Med, Dept Publ Hlth Environm & Soc, 5-17 Tavistock Pl, London WC1H 9SH, England
[2] UCL, Royal Free Hosp, Inst Global Hlth, Rowland Hill St, London NW3 2PF, England
[3] UCL, Med Res Council, Clin Trials Unit, 90 High Holborn, London WC1V 6LJ, England
[4] London Sch Hyg & Trop Med, Dept Global Hlth & Dev, 5-17 Tavistock Pl, London WC1H 9SH, England
[5] HIV I Base, 107 Maltings,169 Tower Bridge Rd, London SE1 3LJ, England