Where is the flu vaccine injected on your body?

• The flu shot is usually given as an intramuscular (IM) needle injection into the upper, outer arm muscle called the deltoid muscle in people 3 years of age and older.
• The preferred injection site for infants and young children is the front, outer area of the thigh.
• The Centers for Disease Control and Prevention (CDC) recommends that everyone 6 months of age and older (with rare exceptions) receive a flu vaccine every year, typically in Sept. or Oct. This is the best way to protect yourself and those around you from the flu virus.

In the U.S., flu shots are administered by a healthcare provider in the fall each year at a pharmacy, clinic or doctor's office. It takes about two weeks to build up your immunity against the flu after your vaccine.

• Flu shots are most commonly given in September and October. Ideally you should get your flu shot by the end of October, but it’s never too late to get your vaccine if you missed the fall timeline.
• Flu activity typically peaks from December through March in the U.S. CDC continues to recommend vaccination as long as flu viruses pose a threat, which can be as late as May or June in some flu seasons.

Related: How is an intramuscular shot given?

What are the brand names of the flu shots?

The best flu shot for you will vary based on your age and if you have certain medical conditions or allergies. Ask your healthcare provider which vaccine is best for you or your child. Names of common flu vaccine injections in the U.S. include:

• Afluria Quadrivalent
• Fluarix Quadrivalent
• Fluzone Quadrivalent
• Fluzone High-Dose Quadrivalent
• Fluad Quadrivalent
• Flublok Quadrivalent
• Flucelvax Quadrivalent
• FluLaval Quadrivalent

Learn more: Should You Get Your Flu Vaccine Now?

Is the flu shot painful?

You may have some injection site pain that usually clears up in a few days, and this is normal. The flu shot is given as an intramuscular (IM) injection. The pain with a flu shot injected into muscle is usually minor and short-lived, and most people have few troubles.

Ask your doctor if you can take some acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) after your shot if needed.

What are the most common side effects of a flu shot?

Beside minor pain, other flu shot injection site reactions can occur. Side effects of the flu vaccine are generally mild symptoms and go away on their own within a few days.

Common flu shot side effects may include:

• soreness, swelling or red area around flu shot injection site
• headache
• fever
• nausea
• muscle aches
• occasional fainting

Life threatening allergic reactions or severe symptoms to the flu shot are rare. Signs of a severe allergic reaction would most likely happen within a few minutes to a few hours after the vaccine is given and can include:

• trouble breathing, shortness of breath
• hoarseness or wheezing
• swelling on the face, for example, around the eyes or lips
• hives (a red welt or itchy injection site after flu shot)
• looking pale
• feeling weak or dizzy
• a fast heart beat

A small rash at the injection site of the flu shot may not be a severe allergic reaction, but always check with your healthcare provider.

• Influenza virus vaccine (injection) side effects (in more detail)

If you think you are having a severe allergic reaction to any flu vaccine, or have a high fever or unusual behavioral changes, call 911, your doctor, or other medical emergency help immediately.

Are there any flu vaccines without needles?

Yes, there are two flu vaccines available without needles: the Afluria Quadrivalent given via the PharmaJet Stratis Needle-Free Injector (a “jet injector”) and the intranasal FluMist vaccine.

Afluria Quadrivalent can be given via a needle-free jet injector or with a needle.

• If you are 18 through 64 years of age and are eligible for a flu vaccine, you can request needle-free Afluria. First check with your doctor, clinic, or pharmacy to be sure they have the jet injector. Call your insurance to be sure it is covered, too.
• It's not 100% pain-free, but the jet injector creates a narrow stream of fluid that goes through the skin, without a needle, given in one-tenth of one second.
• Children 6 months through 17 years and adults 65 and older can receive Afluria Quadrivalent only by a needle and syringe (not the jet injector).

FluMist is an intranasal flu vaccine spray.

• FluMist Quadrivalent is a needle-free option that is used in certain populations between the ages of 2 to 49 years to help prevent influenza. It is a liquid vaccine that is sprayed into the nose.
• Not everyone can use FluMist. Children under 2 years of age cannot use it due to an increased risk of wheezing. Tell your healthcare provider if you (or your child) are currently wheezing, or have a history of wheezing.
• In addition, anyone with a severe allergy to eggs, anyone who has had a life-threatening allergic reaction to any flu vaccine, and children 2 through 17 years old who take aspirin or medicines containing aspirin cannot use FluMist.

There are additional warnings for people who may not be able to get the FluMist Quadrivalent intranasal vaccine, ask your doctor if you fall into any of those groups.

This is not all the information you need to know about the flu vaccine for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss any questions you have with your doctor or other health care provider.