[Influenza surveillance and control program of WHO]

The World Health Organization(WHO) influenza surveillance network now maintains 110 National Influenza Centers in 83 countries and four WHO Collaborating Centers(London, Atlanta, Melbourne and Tokyo). This network provides useful epidemiological and virological information to decide the recommended vaccine composition each year. Another important role of the network is to detect and analyze potential pandemic strains, since an early detection of pandemic strain is crucial to minimize the impact of the pandemic. WHO continues to improve the global surveillance particularly in China, since China has the important role for the influenza epidemiology in the world. WHO also published Influenza Pandemic Preparedness Plan in 1999.