Fluzone (influenza) is a prescription vaccine used to prevent or reduce the risks of influenza infection. Fluzone can cause side effects that range from mild to serious, including injection site reaction and tiredness.

Specifically, Fluzone is designed to provide immunity against influenza infection caused by influenza subtype A and type B viruses. It’s used in both adults and children.

Fluzone contains two subtype A and two type B inactivated influenza strains. The vaccine comes as a liquid suspension that’s injected into your upper arm muscle or the mid-thigh muscle for infants and toddlers. Fluzone is available in two different forms:

  • Fluzone Quadrivalent for people ages 6 months and older
  • Fluzone High-Dose Quadrivalent for people ages 65 years and older

Keep reading to learn about the common, mild, and serious side effects Fluzone can cause. For a general overview of the vaccine, including details about its uses, see this article.

Below are just a few of the more common side effects reported by people who took Fluzone or Fluzone High-Dose in studies. These side effects can vary depending on the person’s age at the time of vaccination.

More common side effects in children ages 6 to 36 months receiving the Fluzone Quadrivalent include:

More common side effects of Fluzone Quadrivalent in children ages 3 years through adults ages 64 years include:

  • pain, discoloration, and swelling at the injection site*
  • headache*
  • tiredness
  • muscle aches and general body discomfort

The more common side effects in adults ages 65 years and older taking Fluzone High-Dose Quadrivalent (also known as the senior flu shot) include:

  • muscle aches and general body discomfort
  • pain at the injection site*
  • headache*
  • tiredness

* To learn more about this side effect, see the “Side effects explained” section below.

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

  • tiredness or drowsiness
  • fever and chills*
  • loss of appetite
  • vomiting
  • soreness or swelling of lymph nodes in the underarm or neck
  • muscle aches and general body discomfort
  • headache*
  • dizziness and fainting
  • injection site reactions*

In most cases, these side effects should be temporary. And some may be easily managed with acetaminophen, fluids, and rest. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist.

Fluzone may cause mild side effects other than those listed above. See the prescribing information for Fluzone or Fluzone High-Dose for details.

* To learn more about this side effect, see the “Side effects explained” section below.

Rare but serious side effects have been reported with Fluzone and Fluzone High-Dose. These include:

If you develop serious side effects from 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.

Note: After the Food and Drug Administration (FDA) approves a vaccine, it and the Centers for Disease Control and Prevention (CDC) track side effects of the vaccine. If you’d like to report a side effect you’ve had with Fluzone, visit the Vaccine Adverse Event Reporting System (VAERS) website.

Get answers to some frequently asked questions about Fluzone’s side effects.

What should I avoid after the flu shot?

The purpose of Fluzone is to activate your immune system to produce flu-fighting blood cells and antibodies. You want your body to produce the best response possible, so a few things to avoid after receiving Fluzone include:

  • excessive amounts of alcohol
  • strenuous exercise (light exercise is OK)
  • fasting from food

Overall, it’s safe to return to your normal daily activities after a Fluzone vaccine, but listen to your body. Resting, eating a well-balanced diet, and drinking plenty of fluids for 24 hours after the vaccine will help your body produce a strong immune response.

What are the long-term side effects of the flu vaccine?

Long-term side effects from Fluzone are extremely rare. Examples of long-term side effects reported in Fluzone and Fluzone High-Dose studies include:

  • life threatening allergic reactions
  • Guillain-Barré syndrome (GBS)

Vaccinations are given by pharmacists, nurses, or doctors who have received special training in performing cardiopulmonary resuscitation (CPR) and managing anaphylaxis. So the risk of long-term complications from an allergic reaction is rare.

GBS causes muscle weakness and nerve tingling that often begins in the feet and hands before moving to other body areas. Severe symptoms can result in paralysis. Most people make a full recovery from GBS, but some can have long lasting problems such as nerve pain and difficulty walking.

If you have concerns about long-term side effects from Fluzone, talk with your doctor or pharmacist.

What side effects will I have a week after a flu jab?

Side effects from Fluzone should only last 1 to 2 days following injection. If you have symptoms lasting a week or longer, check with your doctor or pharmacist, as these symptoms may be caused by something else.

Is diarrhea a potential side effect of the Fluzone shot?

Diarrhea (also spelled diarrhoea) was not a side effect reported in studies of Fluzone or Fluzone High-Dose. But people who are prone to loose stools may experience diarrhea from any vaccination. If you have concerns about Fluzone causing diarrhea, speak with your doctor or pharmacist.

Learn more about some of the side effects Fluzone may cause and the best ways to relieve flu shot side effects.

Fever and chills

Fever and chills were common side effects reported in studies of Fluzone and Fluzone High-Dose.

A body temperature of 100.4°F (38.0°C) or higher was considered a fever in Fluzone studies. Infants and children were more likely to run a fever after vaccination. The risk of seizure from a fever may be higher the day of and the day after a flu vaccine. Seizure caused by fever was a rare side effect in infant and child studies of the drug.

Also, children who received a 13-valent pneumococcal conjugate vaccine (PCV13) and a diphtheria, tetanus, and acellular pertussis (DTaP) vaccine on the same day as a flu vaccine were more likely to have a fever with seizures.

Adults are more likely to have chills than a fever.

What might help

If you have a fever or chills after a Fluzone vaccine, consider the following:

  • taking acetaminophen
  • drinking fluids
  • getting plenty of rest
  • wearing loose-fitting, comfortable clothing

Talk with the pediatrician if your child’s fever goes above 102°F (38.9°C). Adults should call their doctor if their fever goes above 103°F (39.4°C) or if they have any fever with a low immune system diagnosis.

Injection site reactions

Injection site reactions were a common side effect reported in studies of Fluzone and Fluzone High-Dose.

Injection site reactions may cause symptoms at the site where the vaccine was injected, such as:

  • pain or tenderness
  • a hardened lump
  • red, dark, or discolored skin
  • bruising
  • swelling

Factors that can increase the risk of injection site reactions with Fluzone include:

  • incorrect position of your arm
  • an allergy to vaccine ingredients
  • the vaccine being cold when it’s injected

What might help

You can reduce the risk of injection site reactions after a Fluzone vaccine by:

  • relaxing with your arm down by your side
  • wearing a loose-fitting, short-sleeve shirt or completely removing your arm from a long-sleeve shirt
  • avoiding forceful rubbing of the injection site
  • reminding your doctor or pharmacist about your history of vaccine reactions

If you develop a reaction at the injection site, the following may help relieve your symptoms:

  • taking acetaminophen to reduce pain
  • applying a cold compress to reduce swelling
  • moving the arm to increase blood circulation


Headache was a common side effect reported in studies of Fluzone and Fluzone High-Dose. Headache from a vaccine is usually mild and improves within 24 hours.

Headache may cause symptoms such as tiredness, nausea, and head, neck, or back pain. Factors that can increase the risk of headache from a Fluzone vaccine include dehydration, hunger, and lack of sleep.

What might help

To reduce your risk of getting a headache after receiving a Fluzone vaccine, try these tips for preparation:

  • drinking plenty of water
  • eating well-balanced meals
  • getting a good night’s rest

If you develop a headache after your Fluzone vaccination, consider the following:

  • resting
  • drinking plenty of fluids
  • taking acetaminophen for pain reduction

If you have more questions about how to treat a vaccine headache, talk with your doctor or pharmacist.

Allergic reaction

For some people, Fluzone or Fluzone High-Dose can cause an allergic reaction.

In general, symptoms of an allergic reaction can be mild or serious. You can learn more about possible symptoms in this article.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and determine whether you should receive future flu vaccines.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Fluzone, they may tell you not to receive another flu vaccine.

Fluzone Quadrivalent vaccine is used to help prevent influenza infection in children ages 6 months and older.

The following side effects were reported more commonly in children than in adults in the vaccine’s studies.

  • fever
  • vomiting
  • loss of appetite
  • irritability and crying
  • seizure caused by fever (this was a rare side effect)

For more information about potential side effects of Fluzone in children, talk with your doctor or pharmacist.

Keeping track of side effects

After your Fluzone vaccination, consider taking notes on any side effects you’re having. You can then share this information with your doctor.

Your side effect notes can include things such as:

  • how soon you had the side effect after the vaccine
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Fluzone affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before receiving a Fluzone vaccine.


Fluzone can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Fluzone is a good vaccine option for you.

Talk with your doctor about your health history before any Fluzone shots. Be sure to tell them if any of the following factors apply to you:

  • active moderate to severe illness
  • history of Guillain-Barré syndrome (GBS)
  • egg allergy
  • history of seizure
  • history of Bell’s palsy (one-sided facial drooping or stiffness)
  • weakened immune system
  • taking any prescription medications, over-the-counter (OTC) drugs, herbs, nutritional supplements, or vitamins
  • previous allergic reaction to Fluzone
  • pregnancy
  • breastfeeding

Alcohol and Fluzone

There are no known interactions between alcohol and Fluzone. But alcohol may worsen the side effects of general body discomfort, tiredness, and headache. So it may be best to avoid alcohol until your side effects subside.

If you have questions about consuming alcohol after a Fluzone vaccination, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Fluzone

Before receiving a Fluzone Quadrivalent vaccine, it’s important to talk with your doctor if you’re pregnant, breastfeeding, or planning to become pregnant or breastfeed.


Fluzone Quadrivalent is generally considered safe to receive during pregnancy. The CDC recommends the yearly flu vaccine for all pregnant people in order to lower the risk of influenza infection complications, including:

  • hospitalization
  • miscarriage or stillbirth
  • premature labor and birth
  • infant developmental problems
  • reduced infant birth weight

But if you’re pregnant or planning a pregnancy, you should still talk with your doctor before getting a Fluzone vaccine.

If you receive a Fluzone Quadrivalent vaccine while pregnant, consider signing up for the Sanofi Pasteur Pregnancy Registries by calling 800-822-2463. A pregnancy registry collects information about the safety of certain vaccines when used during pregnancy.


Fluzone Quadrivalent is generally considered safe while breastfeeding. The CDC recommends that breastfeeding women get a flu vaccine because it can increase the amount of influenza antibodies in breast milk. This can boost the breastfeeding child’s immunity against an influenza infection.

But if you’re breastfeeding or planning to do so, you should still talk with your doctor before receiving a Fluzone vaccine.

Disclaimer: Healthline 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.