1. HIV Laboratory, Department of Infectious Disease Epidemiology, National Public Health Institute, FIN-00300 Helsinki, Finland
2. D.I. Ivanovsky Institute of Virology, Russian Academy of Medical Science, Moscow, Russia
3. Russian AIDS Center, Moscow, Russia
4. St. Petersburg Pasteur Institute, St. Petersburg, Russia
5. UNAIDS-Joint United Nations Programme on HIV/AIDS, Geneva, Switzerland