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.

Flublok Quadrivalent 2023-2024 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.

Flublok Quadrivalent 2023-2024 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 Flublok Quadrivalent 2023-2024 (flu shot) is made from "killed viruses." This medicine 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, Flublok Quadrivalent 2023-2024 may not provide protection from disease in every person.

Flublok Quadrivalent 2023-2024 is made from "killed viruses" and will not cause you to become ill with the flu virus.

Some brands of this vaccine are made for use in adults and not in children. Your child's vaccination provider can recommend the best Flublok Quadrivalent 2023-2024 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 Flublok Quadrivalent 2023-2024 is usually given in October or November. Follow your doctor's instructions or the schedule recommended by your local health department.

Since the Flublok Quadrivalent 2023-2024 is redeveloped each year for specific strains of influenza, you should receive a flu vaccine every year.

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:

• a weak immune system (caused by disease or by using certain medicine); or

• a history of Guillain-Barre syndrome (within 6 weeks after receiving a flu vaccine).

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.

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

An overdose of this vaccine is unlikely to occur.

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

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 Flublok Quadrivalent 2023-2024 in the future, you will need to tell the vaccination provider if the previous shot caused any side effects.

Flublok Quadrivalent 2023-2024 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.

Flublok Quadrivalent 2023-2024 may cause serious side effects. Call your doctor at once if you have:

• a light-headed feeling, like you might pass out;

• severe weakness or unusual feeling in your arms and legs;

• numbness, pain, tingling, burning or prickly feeling;

• vision or hearing problems; or

• a fever higher than 101 degrees F.

Common side effects of Flublok Quadrivalent 2023-2024 may include:

• pain, redness, tenderness, swelling, bruising, or a hard lump where the shot was given;

• diarrhea, loss of appetite;

• muscle pain;

• headache, tiredness; or

• fussiness, crying, or drowsiness in a child.

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.

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:

• steroid medicine;

• medications to treat psoriasis, rheumatoid arthritis, or other autoimmune disorders; or

• medicines to treat or prevent organ transplant rejection.

This list is not complete. Other drugs may affect Flublok Quadrivalent 2023-2024, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.