Key Takeaways

The flu shot is usually given as an intramuscular (IM) needle injection into the upper, outer arm muscle (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 US Centers for Disease Control and Prevention (CDC) recommends that everyone 6 months of age and older (with rare exceptions) receive a flu vaccine every fall, typically in September or October. This is the best way to protect yourself and those around you from the flu virus.

In 2025-2026, several types of vaccines are available, including egg-based and egg-free, special vaccines for people over 65 years of age, and adjuvanted vaccines that help to create a stronger immune response from the shot.

To read more about how the flu shot is given you might consider reading How is an intramuscular shot given?

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 no major side effects.

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

If you've had a previous serious reaction to a flu vaccine, be sure to tell your healthcare provider.

Where to get a flu shot in the fall of 2025

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 virus after your vaccine.

Flu shots are usually 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. The CDC states that early vaccination may be considered for certain groups.

Flu activity typically peaks from December through March in the US. The CDC continues to recommend vaccination as long as flu viruses pose a threat, which has been as late as May or June during some flu seasons.

Which flu shots are available this year?

Names of common flu vaccine injections for the 2025-2026 flu season in the US include:

Egg-based vaccines (ages 6 months and older):

• Afluria
• Fluarix
• FluLaval
• Fluzone

Egg-based vaccine (for individuals 65 years and older)

• Fluzone High-Dose

Egg-free, cell-based vaccine (for use in people 6 months of age and older)

• Flucelvax

Recombinant vaccine (for use in people 9 years of age and older)

• Flublok

Adjuvanted vaccine - An adjuvant is an ingredient that helps create a stronger immune response.

• Fluad (for individuals 65 years and older)

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 to help you decide which vaccine is best for you, and for your child.

Trivalent flu vaccines

In the 2025-2026 flu season, all flu vaccines are trivalent, which means that they protect against 3 influenza strains: an H1N1 A virus, an H3N2 A virus, and one influenza B (Victoria lineage) virus. Flu vaccines longer contain 4 strains (are quadrivalent) because the B/Yamagata lineage viruses have not been detected globally since March 2020, and the risk of infection is considered low.

To review more information about flu shot timing you can read Should You Get Your Flu Vaccine Now?

Will flu vaccines contain a preservative this year?

Most of influenza vaccine supply available this flu season will be thimerosal-free or thimerosal-reduced (i.e., preservative-free).

For the 2025-2026 flu season, CDC recommends seasonal flu vaccination with single-dose formulations that are free of thimerosal as a preservative for children, pregnant women, and adults.

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
• 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.

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.

Here you can review Influenza virus vaccine (injection) side effects in more detail.

Are there any flu vaccines without needles?

Yes, there are two flu vaccines available without needles in the 2025-2026 flu season: Afluria given via the PharmaJet Stratis Needle-Free Injector (a “jet injector”) and the intranasal FluMist vaccine, a nasal spray.

1. Afluria needle-free jet injector

Afluria 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. via a jet injector. 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.

A flu vaccine given by a jet injector is 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 by a needle and syringe (not with the jet injector).

2. FluMist

FluMist is is an intranasal (sprayed into the nose) flu vaccine and 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. You can breathe normally while getting FluMist. There is no need to inhale or sniff it.

People 9 years of age and older need one dose of FluMist each year. Children 2 through 8 years of age may need 2 doses of FluMist, depending on their history of previous influenza vaccination.
Your healthcare provider will decide if your child needs a second dose

Not everyone can use FluMist. You should not get FluMist if you:

• have a severe allergy to eggs or to any inactive ingredient in the vaccine
• have ever had a severe allergic reaction to influenza vaccinations.
• are 2 through 17 years of age and take aspirin or medicines containing aspirin. Children or adolescents should not be given aspirin for 4 weeks after getting FluMist unless your healthcare provider tells you otherwise.

Please talk to your healthcare provider if you are not sure if the items listed above apply to you or your child.

Children under 2 years of age have an increased risk of wheezing (difficulty with breathing) after getting FluMist

Let your healthcare provider know if you are pregnant or nursing.

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

If you or your child cannot get FluMist, you may still be eligible to get a flu vaccine injection. Talk to your healthcare provider about this.

FluMist for home use

FluMist for self- or caregiver administration was approved in 2024 and is now available for 2025-2026 influenza season by ordering online. It will still require a prescription, but can be administered at home. FluMist for home use can be ordered and approved online and sent to your home via delivery.

If you are giving FluMist to yourself or someone else, read the “Instructions for Use” that comes with FluMist. Individuals 2 through 17 years of age should not give themselves FluMist. If you have questions, call your pharmacist.

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

References

• Who needs a flu vaccine? 10/3/2024. Centers for Disease Control and Prevention (CDC). Accessed Sep 3, 2025 at https://www.cdc.gov/flu/vaccines/vaccinations.html 
• Flu Vaccine Safety. 8/25/2023. Centers for Disease Control and Prevention (CDC). Accessed Sep 3, 2025 at https://www.cdc.gov/flu/vaccine-safety/
• 2025-2026 Flu Season. 8/6/2025. Centers for Disease Control and Prevention (CDC). Accessed Sep 3, 2025 at https://www.cdc.gov/flu/season/2025-2026.html#

Read next

See also:

Related medical questions

• How well does the flu vaccine work?
• How can I get a flu vaccine without a needle?
• Which flu vaccines are available this year?
• When is the best month to get the flu vaccine?
• Can I get FluMist and the COVID vaccine at the same time?
• What is the difference between Flublok and Flublok Quadrivalent?

Related support groups

• FluMist (9 questions, 5 members)
• Fluarix (6 questions, 3 members)
• Flublok (6 questions, 3 members)
• Fluzone High-Dose (6 questions, 4 members)
• Influenza Virus Vaccine, Inactivated (6 questions, 3 members)
• Fluzone (6 questions, 4 members)
• Afluria (6 questions, 6 members)
• Flucelvax (6 questions, 3 members)
• Flublok Quadrivalent (5 questions, 4 members)
• Fluad (5 questions, 3 members)
• FluMist Quadrivalent (5 questions, 3 members)

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