Fluzone (influenza) is a brand-name vaccine that’s used for preventing the flu. As with other drugs, Fluzone can cause side effects, such as muscle aches or injection site reaction.

Fluzone can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who received Fluzone and Fluzone High-Dose in clinical trials:

  • muscle aches
  • headache
  • injection site reactions (See “Side effect specifics”)

Mild side effects can occur with Fluzone use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Fluzone or Fluzone High-Dose’s prescribing information.

Mild side effects that have been reported with Fluzone and Fluzone High-Dose include:

  • muscle aches
  • headache
  • fever
  • injection site reaction*
  • feeling generally unwell or tired*

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Fluzone and want to tell the FDA about it, visit the Vaccine Adverse Event Reporting System.

* For more information about this side effect, see “Side effect specifics.”

Fluzone may cause serious side effects, but they are very rare. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Fluzone or Fluzone High-Dose’s prescribing information.

If you or your child develops serious side effects while taking Fluzone, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

  • Guillain-Barré syndrome, which may include symptoms such as:
    • numbness and tingling
    • weakness
  • febrile seizure in children (seizure caused by a fever), which may include symptoms such as:
    • body twitches or shakes
    • eyes appearing to roll back
    • body stiffness
ALLERGIC REACTION

For some people, Fluzone can cause an allergic reaction.

In general, symptoms of allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Fluzone, your doctor may recommend taking a different medication instead.

Fluzone may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Does Fluzone cause long-term side effects?

It’s possible. Guillain-Barré syndrome (GBS) can occur with Fluzone, but it is extremely rare.

GBS can cause tingling and weakness in the hands or feet, which may also spread to other parts of the body. In severe cases, it can result in paralysis. After receiving treatment, most people will fully recover from GBS. In some cases, it may cause long-term problems such as nerve pain and difficulty walking.

Talk with your doctor or pharmacist if you have questions about the long-term side effects of Fluzone.

How do side effects of Fluzone in children compare with side effects seen in adults?

Most side effects in children are similar to those seen in adults.

In children, injection site reactions were the most common side effects reported in clinical trials. Some additional side effects were seen in children ages 6 months through 35 months that didn’t occur in adults. These side effects include:

  • fever
  • drowsiness
  • irritability
  • abnormal crying
  • vomiting
  • loss of appetite

If you have questions about the side effects of Fluzone in your child, talk with their doctor or pharmacist.

How long do the side effects of the flu shot last?

Side effects from Fluzone typically last 1 to 2 days after your injection.

Talk with your doctor if you have side effects that don’t go away after a week or longer. They’ll likely want to check to see if your symptoms are due to something else.

Learn more about some of the side effects that Fluzone may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Fluzone or Fluzone High-Dose.

Injection site reaction

Fluzone is given as a shot into the muscle of the arm. Some people experience injection site reactions after receiving the flu shot. This was a common side effect reported in clinical trials of Fluzone or Fluzone High-Dose. Injection site reactions that may occur at the site of the injection include:

  • pain or tenderness
  • swelling
  • skin discoloration

What you can do

Injection site reactions will typically go away on their own.

If you develop an injection site reaction, there are some steps you can take to help relieve the symptoms if they bother you. Moving your arm after the shot will help decrease muscle soreness. Applying a cold compress may help reduce pain and swelling. Your doctor may recommend an over-the-counter pain medication, such as acetaminophen (Tylenol), which can help relieve pain.

Talk with your doctor if you experience an injection site reaction that doesn’t go away or gets worse over time.

Feeling generally unwell or tired

Some people report feeling tired or generally unwell (also called malaise) after receiving their flu shot. This was a common side effect reported in clinical trials of Fluzone and Fluzone High-Dose. You may experience symptoms that include:

  • discomfort
  • fatigue
  • overall weakness
  • feel like you have an illness or are sick

What you can do

Your symptoms will usually go away 1 or 2 days after your injection. It may help to rest and drink plenty of fluids during this time.

If your symptoms are severe or don’t go away on their own within 1 to 2 days after the flu shot, talk with your doctor.

Below is important information you should consider before taking Fluzone.

Other precautions

Before taking Fluzone, discuss your health history with your doctor. Fluzone may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if you:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.