Influenza is a serious disease that can lead to hospitalization and sometimes even death. Every flu season is different, and influenza infection can affect people differently. Even healthy people can get very sick from the flu and spread it to others. Over a period of 31 seasons between 1976 and 2007, estimates of flu-associated deaths in the United States range from a low of about 3,000 to a high of about 49,000 people. During recent flu seasons, between 80% and 90% of flu related deaths have occurred in people 65 years and older. "Flu season" in the United States can begin as early as October and last as late as May.
During this time, flu viruses are circulating at higher levels in the U.S. population. An annual seasonal flu vaccine is the best way to reduce the chances that you will get seasonal flu and spread it to others. When more people get vaccinated against the flu, less flu can spread through that community.