[1] Univ Lausanne, CHU Vaudois, Dept Med, Lab AIDS Immunopathogenesis,Div Immunol, CH-1011 Lausanne, Switzerland
[2] Univ Lausanne, CHU Vaudois, Dept Med, Lab AIDS Immunopathogenesis,Div Allergy & Infect, CH-1011 Lausanne, Switzerland
[3] Univ Lausanne, CHU Vaudois, Inst Microbiol, CH-1011 Lausanne, Switzerland
[4] San Raffaele Inst, Div Infect Dis, Milan, Italy
[5] Univ Geneva, Virol Lab, CH-1211 Geneva 4, Switzerland