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Influenza virus vaccine (injection)

Generic name: influenza virus vaccine (injection) [ IN-floo-EN-za-VYE-rus-VAK-seen ]
Brand names: Afluria PF Quadrivalent 2023-2024, Afluria Quadrivalent 2023-2024, Fluad Quadrivalent PF 2023-2024, Fluarix PF Quadrivalent 2023-2024, Flublok Quadrivalent 2023-2024, ... show all 243 brands
Dosage forms: intramuscular solution (recombinant hemagglutinin quadrivalent), intramuscular suspension (adjuvanted preservative-free quadrivalent; high-dose preservative-free quadrivalent; mdck cell derived quadrivalent; preservative-free mdck cell derived quadrivalent; preservative-free quadrivalent; quadrivalent)
Drug class: Viral vaccines

Medically reviewed by Drugs.com on Aug 2, 2023. Written by Cerner Multum.

What is influenza virus vaccine?

Influenza virus ("the flu") is a contagious disease caused by a virus that can spread from one person to another through the air or on surfaces. Flu symptoms include fever, chills, tiredness, aches, sore throat, cough, vomiting, and diarrhea. The flu can also cause sinus infections, ear infections, bronchitis, or serious complications such as pneumonia.

Influenza causes thousands of deaths each year, and hundreds of thousands of hospitalizations. Influenza is most dangerous in children, pregnant women, older adults, and people with weak immune systems or health problems such as diabetes, heart disease, or cancer.

Influenza virus vaccine is for use in adults and children at least 6 months old, to prevent infection caused by influenza virus. This vaccine helps your body develop immunity to the disease, but will not treat an active infection you already have.

Influenza virus vaccine is redeveloped each year to contain specific strains of inactivated (killed) flu virus that are recommended by public health officials for that year.

The injectable influenza virus vaccine (flu shot) is made from "killed viruses." Influenza virus vaccine is also available in a nasal spray form, which is a "live virus" vaccine. This medication guide addresses only the injectable form of this vaccine.

Like any vaccine, influenza virus vaccine may not provide protection from disease in every person.

Influenza virus vaccine side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

You should not receive a booster vaccine if you had a life threatening allergic reaction after the first shot.

Keep track of any and all side effects you have. If you receive an influenza virus vaccine in the future, you will need to tell the vaccination provider if the previous shot caused any side effects.

Influenza virus vaccine is made from "killed viruses" and will not cause you to become ill with the flu virus. You may have flu-like symptoms at any time during flu season that may be caused by other strains of influenza virus.

Influenza virus vaccine may cause serious side effects. Call your doctor at once if you have:

Common side effects of influenza virus vaccine may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report vaccine side effects to the US Department of Health and Human Services at 1-800-822-7967.

Warnings

Influenza virus vaccine is made from "killed viruses" and will not cause you to become ill with the flu virus.

Before taking this medicine

You may not be able to receive this vaccine if you are allergic to eggs, or if you have ever had a severe allergic reaction to a flu vaccine.

Tell your vaccination provider if you have:

You can still receive a vaccine if you have a minor cold. In the case of a more severe illness with a fever or any type of infection, wait until you get better before receiving this vaccine.

Tell your vaccination provider if you are pregnant or breastfeeding.

The Centers for Disease Control and Prevention recommends that pregnant women get a flu shot during any trimester of pregnancy to protect themselves and their newborn babies from flu. The nasal spray form of influenza vaccine is not recommended for use in pregnant women.

How is this vaccine given?

Some brands of this vaccine are made for use in adults and not in children. Your child's vaccination provider can recommend the best influenza virus vaccine for your child.

This vaccine is given as an injection (shot) into a muscle.

Children 6 months to 8 years old may need a second flu shot 4 weeks after receiving the first vaccine.

The influenza virus vaccine is usually given in October or November. Follow your doctor's instructions or the schedule recommended by your local health department.

Since the influenza virus vaccine is redeveloped each year for specific strains of influenza, you should receive a flu vaccine every year.

Influenza virus vaccine dosing information

Usual Adult Dose for Influenza Prophylaxis:

0.5 mL, IM, once


Fluzone Intradermal(R):
0.1 mL, intradermally, once

Usual Pediatric Dose for Influenza Prophylaxis:

6 months to 35 months: 0.25 mL, IM - 1 or 2 doses; if 2 doses, administer 1 month apart
3 to 8 years old: 0.5 mL (1 dose), IM - 1 or 2 doses; if 2 doses, administer 1 month apart
9 years and older: 0.5 mL, IM, once

Comments:
-Previously unvaccinated children (under 9 years of age) should receive 2 doses.
-Some previously vaccinated children should receive 2 doses: check current ACIP guidelines.
-Check the approved age range for the vaccine being used.
-The deltoid muscle of the upper arm is the preferred administration site.

What happens if I miss a dose?

Call your doctor if you forget to receive your yearly flu shot in October or November, or if your child misses a booster dose.

What happens if I overdose?

An overdose of this vaccine is unlikely to occur.

What should I avoid before or after receiving this vaccine?

Follow your vaccination provider's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect influenza virus vaccine?

If you are using any of these medications, you may not be able to receive the vaccine, or may need to wait until the other treatments are finished:

This list is not complete. Other drugs may affect influenza virus vaccine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Popular FAQ

Egg-free vaccines include Flublok Quadrivalent, for people 18 years and older and Flucelvax Quadrivalent for people 6 months and older. The CDC now states that people with egg-allergy may receive any flu vaccine appropriate for their age and health status. Continue reading

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 CDC recommends that everyone 6 months of age and older receive a flu vaccine every year, typically in Sept. or Oct. Continue reading

Flu vaccination typically reduces the risk of flu illness by between 40% and 60% during seasons when the flu viruses are well-matched to the flu vaccine. But if you are infected with the virus, the vaccine reduces your chances of getting the flu and passing it on to others and lessens the severity of symptoms, hospitalizations and death. Continue reading

Options that are available for a needle-free flu vaccine are the FluMist Quadrivalent nasal spray and the Afluria Quadrivalent vaccine given with the Stratis needle-free jet injector. Check with your healthcare provider to see if you are eligible. Continue reading

You can find the flu vaccine most quickly at your local pharmacy, where you can usually walk in without an appointment. To save time, you might prefer to make an appointment. Call your pharmacist to be sure they have the current year's vaccine in stock. Continue reading

View more FAQ

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.