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.

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.

Use Afluria Quadrivalent 2021-2022 (Intramuscular) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

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.

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 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.

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