[1] Univ London Imperial Coll Sci Technol & Med, St Stephens Ctr, Chelsea & Westminster Hosp, Int AIDS Vaccine Initiat,Core Lab, London SW10 9NH, England
[2] Univ Witwatersrand, Dept Mol Med & Haematol, Johannesburg, South Africa
[3] Natl Inst Communicable Dis, Johannesburg, South Africa
[4] AFRIMS Henry M Jackson Fdn, Dept Retrovirol, Bangkok, Thailand