The most important groups of persons who should get flu shots are those who are at highest risk for developing serious complications from the flu. A yearly flu shot is recommended for the following groups of people who are at increased risk for serious complications from the flu:

• Persons aged over 50 years;*

• Residents of nursing homes and other long-term care facilities that house persons of any age who have long-term illnesses;

• adults and children over 6 months of age who have chronic heart or lung conditions, including asthma;

• Adults and children over 6 months of age who need regular medical care or had to be in a hospital because of metabolic diseases (like diabetes), chronic kidney disease, or weakened immune system (including immune system problems caused by medicine or by infection with human immunodeficiency virus [HIV/AIDS]);

• Children and teenagers (aged 6 months to 18 years) who are on long-term aspirin therapy and therefore could develop Reye Syndrome after the flu; and

• Women who will be more than 3 months pregnant during the flu season.
• Persons with chronic diseases of the heart, lungs, or kidneys
• Persons with a severe form of anemia

*People 50-64 years of age who do not have chronic (long-term) medical conditions might not be at high risk for serious complications from the flu.  However, about 26% of people aged 50-64 years have high-risk conditions and are at increased risk for flu-related complications.  Beginning in 2000, a flu shot was recommended for all people 50-64 years old each year to increase the number of high-risk 50-64 year olds who get a flu shot.

Because young, otherwise healthy children are at increased risk for influenza-related hospitalization, influenza vaccination of healthy children aged 6-23 months is encouraged when feasible.

The vaccine can be given to children as young as 6 months. Children and teenagers (aged 6 months to 18 years) should get the flu vaccine if they are taking long-term aspirin treatment as they may be at risk of developing Reye's syndrome following a flu infection (see section on complications in children). They should also get the flu vaccine if they live in a household with someone in the above groups.

Health care workers and volunteers should get the flu vaccine if they work with patients in any of the above groups.