What is influenza?

Influenza (also called "the flu") is a viral infection in the nose, throat and lungs. About 10% to 20% of Americans get the flu each year. Some people can get very sick from the flu. Each year, about 200,000 people go to a hospital with the flu, and 36,000 people die because of the flu and complications.

The flu may cause fever, cough, sore throat, a runny or stuffy nose, headache, muscle aches and tiredness. Most people feel better after 1 or 2 weeks, but for some people, the flu leads to serious diseases, such as pneumonia. The influenza vaccine can help protect you from getting the flu.

Who is at higher risk?

The following people have a higher risk of flu complications:

• All children from 6 months up to 19 years of age
• All adults 50 years of age and older
• All women who are or will be pregnant during the flu season
• People who are living in nursing homes or long-term-care facilities
• Individuals who have long-term health problems
• Health care workers who have direct contact with patients
• Caregivers and household contacts of children less than 6 months of age

What is H1N1 flu?

The H1N1 influenza (also called swine influenza or swine flu) is a respiratory infection caused by a virus found in pigs. H1N1 flu can infect humans. For more information, visit our H1N1 Influenza handout.

How can I avoid getting the flu?

The best way to avoid getting the flu is to get the influenza vaccine. You should get the vaccine as soon as it becomes available each fall, but you can also get it any time throughout the flu season (into December, January and beyond). The vaccine is available by shot or by nasal spray. The vaccines work by exposing your immune system to the flu virus. Your body will build up antibodies to the virus to protect you from getting the flu. The flu shot contains dead viruses. The nasal-spray vaccine contains live but weakened viruses. You cannot get the flu from the flu shot or the nasal-spray vaccine.

You can also reduce your risk of catching the flu by washing your hands frequently, which stops the spread of germs. Eating healthy, exercising and getting enough sleep also play a part in preventing the flu because they help boost your immune system.

If you are sick, make sure that you cover your mouth when you cough and wash your hands often to prevent giving the flu to others.

Some people who get the vaccine will still get the flu, but they may get a milder case than people who aren't vaccinated. The vaccine is especially recommended for people who are more likely to get really sick from flu-related complications.

Should I get the flu vaccine?

Yes. All persons who are 6 months of age or older should get the flu vaccine as long as there are no contraindications.

Is there anyone who shouldn't get the flu shot?

Yes. The following people should talk to their doctor before getting the flu shot:

• People who have had an allergic reaction to a flu shot in the past
• People who have an allergy to eggs
• People who previously developed Guillain-Barré Syndrome (a reversible reaction that causes partial or complete loss of movement of muscles, weakness or a tingling sensation in the body) within 6 weeks of getting a flu shot
• Children younger than 6 months of age
• People who have a moderate or severe illness with a fever should wait until they feel better before receiving the flu shot

Is there anyone who shouldn't get the nasal-spray vaccine?

Yes. The following people should talk to their doctor before getting the nasal-spray vaccine:

• Children less than 2 years of age
• Adults 50 years of age and older
• People who have long-term health problems
• People who have weakened immune systems
• Children or adolescents who are on long-term aspirin therapy
• People who have diabetes, kidney disease, heart disease or lung disease
• People with a history of Guillain-Barré syndrome
• Pregnant women
• People who have had an allergic reaction to a flu vaccine in the past or who are allergic to eggs

If I get the flu vaccine, can I still get the flu?

Yes. Even with a flu vaccine, you aren't 100% protected. Each year, the flu vaccine contains 3 different strains (kinds) of the virus. The strains chosen are those that scientists believe are most likely to show up in the United States that year. If the choice is right, the vaccine can be as much as 70% to 90% effective in preventing the flu in healthy adults. If you're older than 65 years of age, the vaccine is less likely to prevent the flu. Even if you get the flu after being vaccinated, your flu symptoms can be milder than if you didn't get the vaccine. You'll also reduce your risk of complications from the flu.

Is the vaccine safe?

Yes. The flu vaccine is safe. There are very few side effects. If you got the flu shot, your arm may be sore for a few days. You may have a fever, feel tired or have sore muscles for a short time. If you got the nasal-spray vaccine, you may have a runny nose, headache, cough or sore throat.

Can I get the flu vaccine if I am pregnant or nursing?

If you are pregnant during flu season, you cannot get the nasal-spray vaccine. However, it is recommended that women who will be pregnant during flu season get the shot. Pregnancy can increase your risk for complications from the flu.

It is also safe to get the flu shot while breastfeeding your baby. The flu shot cannot cause you or your nursing baby to get sick.

What are antiviral flu drugs?

Antiviral flu drugs are prescription medicines that can be used to help prevent and/or treat the flu. There are four antiviral flu drugs: amantadine, oseltamivir, rimantadine and zanamavir. All 4 of these antiviral drugs have been approved to treat the flu. If you take one of these drugs within 2 days of getting sick, it can lessen your symptoms, decrease the amount of time you are sick and make you less contagious to other people. However, most healthy people who have the flu get better without using an antiviral flu drug. Your doctor will decide whether one of these medicines is right for you.

Three of the antiviral flu drugs have also been approved to prevent the flu. These drugs are not a substitute for the influenza vaccine. They are most often used for flu prevention in institutions where people at high risk for flu complications are in close contact with each other, such as nursing homes or hospitals. For example, during a flu outbreak in a nursing home, residents and staff might be given the flu vaccine and an antiviral drug to prevent the flu until the vaccine takes effect.

Where can I learn more about the flu vaccine?

For more information, you can call the Centers for Disease Control and Prevention's National Immunization Information Hotline at these numbers:

1-800-232-2522 (English)

1-800-232-0233 (Spanish)

Other Organizations