Getting an annual flu shot is especially important for people who are at high risk for infection, such as students (who live and study in crowded areas), health care workers, those who smoke, those over 50 and children under 2 years of age, and those with weakened immune systems (e.g.,due to recent illness). The CDC currently recommends flu vaccine for everyone.
Since the strain of the flu virus changes every year, annual vaccines are needed. It takes about two weeks after vaccination for antibodies to develop in the body that protect against flu, so make plans to get vaccinated early in fall, before flu season begins
Access the CDC Vaccine Information Statement (VIS) here.