1. Influenza Division National Center for Immunization and Respiratory Diseases CDC Atlanta Georgia USA
2. Doherty Department World Health Organization Collaborating Centre for Reference and Research on Influenza Royal Melbourne Hospital University of Melbourne, at the Peter Doherty Institute for Infection and Immunity Melbourne Australia
3. Virology Department Public Health Institute of Chile Santiago Chile
4. Center for Respiratory Diseases and Meningitis National Institute for Communicable Diseases Johannesburg South Africa
5. Faculty of Health Sciences School of Public Health University of the Witwatersrand Johannesburg South Africa