This medication belongs to a group of medications known as vaccines. It is used to prevent influenza (the flu). Influenza is a common viral illness caused by 2 types of virus: influenza A and influenza B.

Each year, different strains (new, slightly different versions of the virus) appear. Scientists predict which strains will be most likely for the coming year, and then these strains are used to make up the year's influenza vaccine. Each year's influenza vaccine contains 3 virus strains that are likely to circulate in Canada in the coming winter. The vaccine only provides protection against the strains of flu virus used to prepare the vaccine.

The vaccine increases a person's defenses against the influenza virus. It works by introducing very small amounts of parts of the virus into the body. This is enough to stimulate the production of antibodies (cells designed to attack that particular virus), which will remain in the body ready to attack that same virus in the future. The vaccine is used to prevent influenza for adults who want to reduce their chances of getting the flu.

Although the National Advisory Committee on Immunization (NACI) recommends annual vaccination for the majority of the population, this particular vaccine is not recommended for people under 18 years of age.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended dose of this vaccine depends on your age. Adults between the ages of 18 and 59 receive a dose of 9 µg of each type of virus. Adults 60 years and older receive a dose of 15 µg of each type of strain. The influenza vaccine is given once a year, usually in October or November, as an intradermal (into the skin) injection, usually in the upper arm. It is given by a health care professional.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important this medication be given exactly as recommended by your doctor. If you miss an appointment to receive intradermal influenza vaccine, contact your doctor as soon as possible to reschedule your appointment.

This medication is stored in the refrigerator and should be kept out of the reach of children. It should be protected from light and not allowed to freeze.

You should not receive this vaccine if you:

• are allergic to any ingredients of this medication
• are allergic to eggs

This medication is not intended to be given to anyone under 18 years of age.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• aches or pains in muscles
• fever or shivering
• general feeling of discomfort or illness
• headache
• itchiness
• tenderness, redness, or a hard lump at the injection site

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• excessive fatigue

Stop taking the medication and seek immediate medical attention if any of the following occur:

• symptoms of a severe allergic reaction (e.g., swollen face or throat, hives, or difficulty breathing)

Be sure to mention any side effect to your doctor, as it may mean that you are allergic to the vaccine. If so, it would not be safe for you to have more doses of the same type of vaccine.

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Allergic reactions: Rarely, this vaccine may cause severe allergic reactions. For this reason, your doctor may ask you to stay in the office for about 30 minutes after having the vaccine so that you can get medical care if you experience an allergic reaction. If you notice signs of a severe allergic reaction (hives; trouble breathing or swallowing; or swelling of the lips, face, throat, or tongue), get medical attention immediately.

Fever: A doctor may decide to delay this vaccine if the person receiving the vaccine has an acute infection or fever. Mild infections without fever, such as colds, usually do not require delay of the vaccine.

Guillain-Barre Syndrome (GBS): Guillain-Barre Syndrome, a neurological disorder, has been rarely reported after this vaccine is given. If you experience any weakness or tingling in the legs, arms, or upper body, contact your doctor. Most people recover fully from GBS.

Immune problems: As with any vaccine, when used for people with weakened immune systems, intradermal influenza vaccine may not create enough of an antibody response to protect against infections caused by these viruses. Also, this vaccine may not be effective for people receiving immunosuppressive therapy (e.g., some medications used to treat cancer or for transplant recipients).

Protection: This vaccine can only protect against the types of virus specific to this vaccine and, as with other vaccines, may not provide 100% protection for everyone who receives the vaccine.

Pregnancy: If you are or may become pregnant while receiving this medication, talk to your doctor about the risks and benefits of using this vaccine. The National Advisory Committee on Immunization recommends influenza vaccination for healthy pregnant women.

Breast-feeding: If you are breast-feeding while receiving this medication, talk to your doctor about the risks and benefits of using this vaccine. The National Advisory Committee on Immunization recommends influenza vaccination for healthy breast-feeding women.

Children: The safety and effectiveness of using this medication have not been established for children under the age of 18 years.

There may be an interaction between intradermal influenza vaccine and any of the following:

• acetaminophen
• alemtuzumab
• anticancer medications (e.g., carboplatin, doxorubicin, irinotecan, vincristine)
• antiviral agents (e.g., amantadine, oseltamivir, ribavirin, zanamivir)
• azathioprine
• belimumab
• corticosteroids (e.g., dexamethasone, prednisone, prednisolone)
• cyclosporine
• daclizumab
• hydroxychloroquine
• mercaptopurine
• methotrexate
• sirolimus
• tacrolimus

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.