H1N1 influenza virus vaccine (injectable)

What is the most important information I should know about this vaccine?

The injectable H1N1 influenza virus vaccine is a "killed virus" vaccine. H1N1 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.

H1N1 influenza is sometimes called "swine flu" because it is usually found in pigs. You cannot become infected with H1N1 influenza from eating pork products.

The injectable form of H1N1 influenza virus vaccine is a "killed virus" vaccine and will not cause you to become ill with the flu virus that it contains. However, you may have flu-like symptoms at any time during flu season that may be caused by other strains of influenza virus.

Do not receive this vaccine if you have ever had an allergic reaction to a flu vaccine, or if you are allergic to eggs.

Before you receive an H1N1 influenza virus vaccine, tell your doctor if you have a weak immune system, or a history of Guillain-Barré syndrome or neurologic disorder affecting the brain (especially if these were caused by a vaccine).

You can still receive an H1N1 influenza vaccine if you have a cold or fever. 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.

Keep track of any and all side effects you have after receiving this vaccine. If you ever have to receive another influenza virus vaccine in the future, you will need to tell the doctor if the first shot caused any side effects.

Like any vaccine, H1N1 influenza virus vaccine may not provide protection from disease in every person. This vaccine will not prevent illness caused by avian flu ("bird flu").

Becoming infected with influenza is much more dangerous to your health than receiving the vaccine to protect against it. Most people with H1N1 influenza have recovered, but the virus has caused some deaths.

What is H1N1 influenza virus vaccine?

H1N1 influenza is sometimes called "swine flu" because it is usually found in pigs. You cannot become infected with H1N1 influenza from eating pork products.

H1N1 influenza virus can spread from one person to another through small droplets of saliva that are expelled into the air when an infected person coughs or sneezes. The virus can also be passed through contact with objects the infected person has touched, such as a door handle or other surfaces.

H1N1 influenza virus vaccine is used to prevent infection caused by the pandemic 2009 H1N1 influenza virus.

The injectable H1N1 influenza virus vaccine is a "killed virus" vaccine. H1N1 influenza virus vaccine is also available in a nasal spray form, which is a "live virus" vaccine.

H1N1 influenza virus vaccine works by exposing you to a small dose of the virus, which helps your body to develop immunity to the disease. This vaccine will not treat an active infection that has already developed in the body.

H1N1 influenza virus injectable vaccine is for use in adults and children who are at least 6 months old.

Becoming infected with influenza is much more dangerous to your health than receiving the vaccine to protect against it. Most people with H1N1 influenza have recovered, but the virus has caused some deaths. Like any medicine, this vaccine can cause side effects, but the risk of serious side effects is extremely low.

Like any vaccine, H1N1 influenza virus vaccine may not provide protection from disease in every person. This vaccine will not prevent illness caused by avian flu ("bird flu").

What should I discuss with my healthcare provider before receiving this vaccine?

Do not receive this vaccine if you have ever had an allergic reaction to a flu vaccine, or if you are allergic to eggs.

Before you receive an H1N1 influenza virus vaccine, tell your doctor if you have:

• a history of Guillain-Barré syndrome (especially if you had it within 6 weeks after having a flu vaccine);
• a weak immune system caused by disease, bone marrow transplant, or by using certain medicines or receiving cancer treatments; or
• a neurologic disorder or disease affecting the brain (or if this was a reaction to a previous vaccine).

You can still receive a vaccine if you have a cold or fever. 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.

Vaccines may be harmful to an unborn baby and generally should not be given to a pregnant woman. However, not vaccinating the mother could be more harmful to the baby if the mother becomes infected with a disease that this vaccine could prevent. Your doctor will decide whether you should receive this vaccine.

It is not known whether H1N1 influenza virus vaccine passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

This vaccine should not be given to a child younger than 6 months old.

How is this vaccine given?

This vaccine is given as an injection (shot) into a muscle. You will receive this injection in a doctor's office or other clinic setting.

Children younger than 10 years old should receive two H1N1 influenza virus vaccine shots spaced one month apart. Older children and adults are usually given only one shot without a booster dose.

Your doctor may recommend treating fever and pain with an aspirin-free pain reliever such as acetaminophen (Tylenol) or ibuprofen (Motrin, Advil, and others) after the shot is given. Follow the label directions or your doctor's instructions about how much of this medicine to take.

It is especially important to prevent fever from occurring if you have a seizure disorder such as epilepsy.

What happens if I miss a dose?

If your child misses a booster dose of this vaccine, call your doctor for instructions.

Be sure to receive all doses of this vaccine recommended by your healthcare provider or by the health department of the state where you live. If you do not receive the full series of vaccines, you may not be fully protected against the disease.

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 doctor's instructions about any restrictions on food, beverages, or activity after you receive this vaccine.

What are the possible side effects of H1N1 influenza virus injectable vaccine?

The injectable form of H1N1 influenza virus vaccine is a "killed virus" vaccine and will not cause you to become ill with the flu virus that it contains. However, you may have flu-like symptoms at any time during flu season that may be caused by other strains of influenza virus.

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 after receiving this vaccine. If you ever have to receive another H1N1 influenza virus vaccine in the future, you will need to tell the doctor if the first shot caused any side effects.

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

Call your doctor at once if you have any of these serious side effects:

• weakness, numbness or tingly feeling in your feet and spreading upward;
• problems with vision, speech, swallowing, or bladder and bowel functions;
• severe lower back pain;
• slow heart rate, trouble breathing, feeling like you might pass out;
• high fever; or
• unusual bruising or bleeding.

Less serious side effects can last a day or two after you receive this vaccine and may include:

• runny or stuffy nose;
• low fever;
• sore throat;
• loss of appetite;
• headache, tired feeling; or
• muscle pain.

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.

What other drugs will affect H1N1 influenza virus injectable vaccine?

Before receiving this vaccine, tell the doctor if you have recently received drugs or treatments that can weaken the immune system, including:

• cancer medicines;
• an oral, nasal, inhaled, or injectable steroid medicine;
• medications to treat psoriasis, rheumatoid arthritis, or other autoimmune disorders, such as azathioprine (Imuran), efalizumab (Raptiva), etanercept (Enbrel), leflunomide (Arava), and others; or
• medicines to treat or prevent organ transplant rejection, such as basiliximab (Simulect), cyclosporine (Sandimmune, Neoral, Gengraf), muromonab-CD3 (Orthoclone), mycophenolate mofetil (CellCept), sirolimus (Rapamune), or tacrolimus (Prograf).

This list is not complete and there may be other drugs that can interact with this vaccine. Tell your doctor about all the prescription and over-the-counter medications you have received. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Where can I get more information?

Your doctor or pharmacist may have information about H1N1 influenza virus vaccine written for health professionals that you may read. You may also find additional information from your local health department or the Centers for Disease Control and Prevention.