1Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
2Division of Viral Pathogenesis, Beth Israel Deaconess Medical Center, Boston, Massachusetts.
3Complejo Hospitalario Xeral-Cíes, Vigo, Pontevedra, Spain.
4Complejo Hospitalario Provincial de Pontevedra, Pontevedra, Spain.
5Hospital de Txagorritxu, Vitoria, Álava, Spain.
6Complejo Hospitalario Santa María Madre, Ourense, Spain.
7Hospital Arquitecto Marcide, Ferrol, A Coruña, Spain.
8Hospital Donostia, San Sebastián, Guipúzcoa, Spain
9Hospital de Basurto, Bilbao, Vizcaya, Spain
10Hospital de Fuenlabrada, Fuenlabrada, Madrid, Spain
11Botkin's Infectious Diseases Hospital, St. Petersburg, Russia.
12St. Petersburg AIDS Center, St. Petersburg, Russia
13National Reference Center of HIV/AIDS, Public Health Institute of Chile, Santiago, Chile.
14Department of Surgery, Laboratory for AIDS Vaccine Research and Development, Duke University Medical Center, Durham, North Carolina.