First, What is a “Flu Shot”

The “flu shot” is an annual treatment to help prevent you from getting sick with the flu each year. The flu vaccination, as with any type of vaccination, is an attempt to get your body to produce antibodies to fight the new flu bug for that year before you actually come in contact with it. This prepares your body to reject the flu when flu season hits. 

• The "flu shot" is an inactivated vaccine (containing killed virus) that is given through a needle in the arm. Note: See also "Who Should Not Get the Flu Vaccine" below.
  
  
• A nasal-spray flu vaccine is now available and it’s made with live, weakened flu viruses that do not cause the flu ( called LAIV for “Live Attenuated Influenza Vaccine”). Vaccination with the nasal-spray flu vaccine is an option for healthy people aged 5-49 years who are not pregnant, and it has been approved for healthy children 2-4 years without a history of recurrent wheezing. Note: Who should not be vaccinated with the nasal-spray? People less than 5 years of age; people 50 years of age and over; people with a medical condition that places them at high risk for complications from influenza, including those with chronic heart or lung disease, such as asthma or reactive airways disease; people with medical conditions such as diabetes or kidney failure; or people with illnesses that weaken the immune system, or who take medications that can weaken the immune system; children or adolescents receiving aspirin; people with a history of Guillain-Barré syndrome, a rare disorder of the nervous system; pregnant women; people with a history of allergy to any of the components of LAIV or to eggs.

When to Get the Flu Vaccine

October or November is the best time of year to get vaccinated, but you can still get vaccinated in December or later. Flu season can begin as early as October and last as late as May.

Who Should Get the Flu Vaccine

Anyone who wants to reduce their chances of getting the flu can usually get vaccinated, but certain people should get vaccinated each year, and are given priority if there is a shortage of flu vaccine; they are either people who are at high risk of having major complications from the flu or the people who live with them, including:

(1) People at high risk for complications from the flu

• People 65 years and older;
• People who live in nursing homes and other long-term care facilities;
• Adults and children 6 months and older with chronic heart or lung conditions, including asthma;
• Adults and children 6 months and older who needed regular medical care or were in a hospital during the previous year because of a metabolic disease (like diabetes), chronic kidney disease, or weakened immune system (including immune system problems caused by medicines or by infection with human immunodeficiency virus [HIV/AIDS]);
• Children 6 months to 18 years of age who are on long-term aspirin therapy;
• Women who will be pregnant during the influenza season;
• All children 6 to 23 months of age;
• People with any condition that can compromise respiratory function or the handling of respiratory secretions (that is, a condition that makes it hard to breathe or swallow, such as brain injury or disease, spinal cord injuries, seizure disorders, or other nerve or muscle disorders.)

(2) People 50 to 64 years old

One-third of people 50 to 64 years of age in the United States have one or more medical conditions that place them at increased risk for serious flu complications, so vaccination is recommended for them.

(3) People who can transmit flu to others at high risk for complications

Any person in close contact with someone in a high-risk group should get vaccinated. This includes health-care workers, household and out-of-home caregivers.

Who Should Not Get the Flu Vaccine

There are some people who should not be vaccinated without first consulting a physician.

• People who have a severe allergy to chicken eggs.
• People who have had a severe reaction to an influenza vaccination in the past.
• People who developed Guillain-Barré syndrome (GBS) within 6 weeks of getting an influenza vaccine previously.
• Influenza vaccine is not approved for use in children less than 6 months of age.
• People who have a moderate or severe illness with a fever should wait to get vaccinated until their symptoms lessen.