[The strategy against influenza].

In France, influenza kills about 2,000 persons per year Among the viruses (M. influenzae A, B and C), type A is the most dangerous because it caused several deadly epidemics. The deepening of knowledge on the mechanisms of infection is essential in the search for new antiviral drugs and more effective vaccines, particularly for developing a vaccine giving long-term immunity. In April 2009, a novel flu strain that combined genes from human, pig, and bird flu, influenza A/H1N1, emerged in Mexico, the United States, and several other nations. The WHO officially declared the outbreak to be a pandemic on June 11, 2009. In 2003, the emerging A(H5N1) influenza virus had been responsible for the largest epizootic event described so far. Facing the fear of a mutation or recombination of the virus, such a pandemic threat has strengthened the public health device and stimulated fundamental, clinical and applied research. Such a mobilization of government and scientific community has been beneficial at the onset of pandemic A(H1N1). WHO continues to monitor A(H1N1) pandemics worldwide, based on results of clinical studies and specific research.