Preparing for the Next Influenza Pandemic

In the past decade, avian influenza has made several incursions of increasing scope and virulence into humans. The likelihood of another pandemic is increasing with time. In work recently published, influenza was found to be the principal cause of the increase in mortality in the United States during the winter months. In a companion report, the U.S. national vaccination program was shown to have increased coverage of high risk groups 5-fold from 1980 to 1999, but excess mortality did not decline in any elderly age group. The Multinational Influenza Seasonal Mortality Study has assembled and has begun to mine mortality data from many countries. Early results indicate that the U.S. results extend to other economically developed countries and probably worldwide.