Vaccines for Pandemic Influenza

The recent outbreak of disease caused by a novel H1N1 virus has focused global attention on the threat of a new influenza pandemic. Recent years have also seen unprecedented outbreaks of avian influenza A viruses. In particular, highly pathogenic H5N1 viruses have not only resulted in widespread outbreaks in domestic poultry, but have been transmitted to humans resulting in numerous fatalities. The rapid expansion in the geographic distribution of these novel viruses raises the risk that such a virus could cause a global pandemic with high morbidity and mortality.