Influenza can make people of any age ill. Although most people are ill for only a few days, some have a much more serious illness and may need to be hospitalized. Thousands of people die each year from influenza-related illnesses.
Most deaths caused by influenza are in elderly people.
People who are at risk for getting a serious case of influenza or a complication should get the vaccine. Anyone who has close contact with people who are at risk for getting a serious case of influenza. The viruses that cause influenza change often, and protection declines within a year after vaccination. So people who need the vaccine should get it every year. The vaccine begins to protect you after 1 to 2 weeks and protection may last up to one year.