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Influenza virus vaccine (By injection)

Influenza Virus Vaccine (in-floo-EN-za VYE-rus VAX-een)

Helps prevent infection with influenza (flu) virus.

Brand Name(s):

Afluria Quadrivalent 2019-2020 Formula, FluLaval Quadrivalent 2017-2018 Formula, FluLaval Quadrivalent 2019-2020 Formula, Fluad 2019-2020 Formula, Fluarix Quadrivalent 2019-2020 Formula, Flublok Quadrivalent 2019-2020 Formula, Flucelvax Quadrivalent 2019-2020 Formula, Fluzone High-Dose 2019-2020 Formula, Fluzone Quadrivalent 2019-2020 Formula

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This vaccine is not right for everyone. You should not receive it if you had an allergic reaction to flu vaccine. If you are allergic to eggs, tell the caregiver who is going to give you the injection. Some brands of this vaccine contain egg proteins and could cause an allergic reaction.

How to Use This Medicine:


  • The vaccine is given as a shot into a muscle or into your skin, usually in the shoulder area. The shot could be given in the thigh for babies and young children.
  • A nurse or other health provider will give you this medicine.
  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
  • A child who is younger than 9 years old and who has not had a flu shot before may need 2 shots. The second shot should be given about 1 month after the first.
  • Missed dose: Most people need only 1 dose of the vaccine. If your child needs a second dose, it is important for the vaccine to be given on schedule. If you must cancel an appointment, make a new one right away.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Tell your doctor if you are using a medicine or treatment that weakens your immune system, such as a steroid, radiation, or cancer treatment. This vaccine may not work as well if you are also using these medicines. However, your doctor may still want you to get the vaccine because it can give you some protection.

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding or if you have a weak immune system.
  • Tell your doctor if you ever had an unusual reaction to a flu shot, such as Guillain-Barré syndrome, or if you are allergic to latex.
  • The flu vaccine may not protect everyone who receives it. This vaccine will not treat flu symptoms if you have already been infected with the virus.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Fainting, dizziness, or lightheadedness
  • Fever over 103 degrees F
  • Seizures
  • Severe muscle weakness

If you notice these less serious side effects, talk with your doctor:

  • Headache, muscle pain, tiredness
  • Irritability or crying (in a child)
  • Redness, pain, swelling, soreness, or a lump where the shot was given

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 5/1/2020

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.

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