Every year, influenza kills 36,000 Americans, mostly among the elderly, though that regular version of flu is usually accompanied by a vaccine that blocks it in most vaccine recipients. Health officials are warning, however, that the world is not prepared for a global flu pandemic, which could occur if prognosticators are wrong about the type of flu that will strike in a given year and create the wrong vaccine to combat it--or if a new kind of flu erupts without warning. Dr. Bruce Gellin, director of the National Vaccine Program Office for the U.S. Department of Health and Human Services, notes that officials are working to prepare for a flu pandemic, and that the international flu surveillance system caught the severe acute respiratory syndrome (SARS) outbreak early in 2003. Gellin adds, however, that new vaccine technologies and flu drugs would be helpful, and "you need the best surveillance possible, particularly in places where you think a virus might emerge."