Seasonal Influenza (Flu)

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Safe vaccines are made each year to protect against the flu. Read on to learn more about the flu from the American Academy of Pediatrics (AAP).

About the Flu

The influenza (flu) virus causes serious illness that may result in hospitalization or death. It mostly affects the breathing system but may also affect the whole body.

The flu season usually starts in the fall and ends in the spring. People can get the flu more than once in the season and many times in their lives. Influenza viruses are unpredictable and often change from year to year.

How to Protect Against the Flu

Get a flu shot every year. The best time is late summer or early fall, or as soon as the vaccine is on hand in your area. If your child does not get the flu shot right away in the fall, it is still important to get it each year. Flu viruses infects people in the fall, in the winter, and well into the spring each year. Your child can still be protected if he or she gets a flu shot as late as the spring months. Ask your child’s doctor if you have any questions about the flu shot.

One kind of inactivated influenza vaccine (IIV) is available for children in the United States for the 2019–2020 season: the quadrivalent vaccine, which has 4 virus strains. The inactivated trivalent vaccine, which has 3 virus strains, is only available for adults.

The IIV is given as an injection into the muscle (intramuscularly). It is licensed and recommended for all infants and children 6 months and older, especially those with a chronic medical condition.

There also is a vaccine that is sprayed into the nose (intranasal) called live, attenuated influenza vaccine (LAIV for short), for those who are healthy and at least 2 years old.

The AAP recommends that any vaccine that is available and is appropriate for the age and health status of your child can be used for vaccination this year. One kind is not preferred over another.

The number of vaccine doses your child needs this year depends on his or her age at the time the first dose is given as well as his or her flu vaccine history.

  • Influenza vaccines are not approved for babies younger than 6 months.

  • Children 9 years and older need only 1 dose.

  • Infants and children 6 months through 8 years of age

    • Need 2 doses if they have never received any flu vaccine or received only 1 dose of flu vaccine in their lives before July 1, 2019

    • Need only 1 dose if they received 2 or more doses of flu vaccine in their lives before July 1, 2019

All people should get the flu vaccine each year to update their protection because

  • The virus strains in the vaccine often change from year to year.

  • The best protection from the flu vaccine usually only lasts for about 6 to 12 months.

Vaccination is especially important for

  • All infants and children (including preterm infants) who are 6 months to 5 years of age

  • Children with health conditions that increase the risk of complications from the flu (such as asthma, other chronic lung diseases, heart conditions, liver or kidney disease, seizures, a weakened immune system, or obesity.)

  • Infants, children, and adolescents (6 months through 17 years of age) receiving an aspirin- or salicylate-containing medication, which places them at risk for Reye syndrome following influenza virus infection

  • Children of American Indian or Alaskan native heritage

  • All household contacts and out-of-home care professionals of children with high-risk conditions and of babies and children younger than 5 years (especially babies younger than 6 months)

  • All health care personnel

  • All child care professionals and staff

  • All women who are pregnant, are considering pregnancy, are in the postpartum period, or are breastfeeding during the flu season

    NOTE: Children with egg allergy of any severity can get influenza vaccine. They can safely receive the flu vaccine without any additional precautions beyond those recommended for any vaccine. Talk with your doctor if you have any questions.

Side Effects of the Flu Vaccine

The flu vaccine has very few side effects. The area where the IIV flu shot is given may be sore for 1 or 2 days. For the LAIV nose spray, common reactions in children are runny nose or nasal congestion, headache, decreased activity or lethargy, and sore throat. Fever may occur within 1 day in about 10% to 35% of infants and children younger than 2 years but rarely occurs in older children and adults.

You or your children will not get the flu from the vaccine. It takes approximately 2 weeks for the vaccine to start working, so people can catch the flu before they are protected if they are not vaccinated until after the flu virus has started to spread in their community. This is why it is important to receive the vaccine before the flu season starts.

Signs and Symptoms of the Flu

All flu viruses cause a respiratory illness that can last a week or more. Flu symptoms include:

  • A sudden fever (temperature usually above 101°F [38.3°C])

  • Chills and body shakes

  • Headache, body aches, and being a lot more tired than usual

  • Sore throat

  • Dry, hacking cough

  • Stuffy, runny nose

Some children may vomit or have diarrhea. Talk with your child’s doctor if your child has ear pain, a cough that will not quit, or a fever that will not go away. Complications as serious as severe pneumonia and death from the flu can occur, but fortunately, these are uncommon.

Ways to Help Your Child Feel Better

Extra rest and a lot of fluids can help your child feel better. You can also give your child medicine if he or she has any aches or pain.

  • For a baby younger than 6 months, give acetaminophen. Tylenol is one brand of acetaminophen. Acetaminophen should not be used for newborns and infants younger than 3 months unless recommended by your baby’s doctor.

  • For an infant or child 6 months and older, give acetaminophen or ibuprofen. Advil and Motrin are brands of ibuprofen.

  • Never give aspirin to any baby or child. Aspirin puts the baby or child at risk for Reye syndrome. This is a serious illness that affects the liver and brain. 

How to Keep Flu Germs From Spreading

The flu virus spreads easily through touching things such as doorknobs or toys and then touching your eyes, nose, or mouth or through the air by coughing and sneezing. Here are some tips that will help protect your family from getting sick.

  • Everyone should wash his or her hands often. You can use soap and warm water for at least 20 seconds. This takes about as long as singing the “Happy Birthday” song 2 times. An alcohol-based hand cleanser or sanitizer works well too. Put enough on your hands to make them wet. Then rub them together until dry.

  • Teach your children to try not to touch their eyes, noses, or mouths.

  • Teach your children to cover their mouths and noses when coughing or sneezing. Show your children how to cough into the elbow or upper sleeve (not a hand) or use a tissue.

  • Throw used tissues into the trash right away.

  • Wash dishes and utensils in hot, soapy water or the dishwasher.

  • Do not share items such as toothbrushes, pacifiers, cups, spoons, forks, washcloths, or towels.

  • Wash doorknobs, toilet handles, countertops, and toys. Use a disinfectant wipe or a cloth with soap and hot water to help kill germs.

When to Call the Doctor

Call the doctor if your child shows signs of the flu and has a chronic medical condition, such as

  • Asthma, diabetes, or other lung or heart problems

  • Sickle cell disease, cancer, HIV, or another disease that makes it hard to fight infections

  • Cerebral palsy or other neurologic disorders of the brain and muscles that make it harder to cough up mucus and breathe

  • Obesity

Call the doctor or go to the emergency department (ED for short) right away if your baby or child shows any signs of the flu and:

  • Is younger than 3 months (12 weeks) and has a temperature of 100.4°F (38.0°C) or higher.

  • Is breathing fast or has any trouble breathing

  • Looks very sick

  • Is sleepier than usual

  • Is very fussy no matter what you do

  • Cannot or will not drink anything

  • Pees very little

  • Has blue skin color

  • Will not wake up at all or is hard to keep calm

Drugs to Treat the Flu

The doctor may be able to treat the flu with a medicine. These drugs work best when your child gets them within the first 1 to 2 days of showing signs of flu.

It is important that you call the doctor within 1 or 2 days of your child’s first symptom to ask about medicine, especially if your child is at high risk of influenza complications because he or she:

  • Has a serious health problem or other lung or heart disease, such as asthma, diabetes, sickle cell disease, or cerebral palsy

  • Is younger than 2 years (Babies and young children are at a greater risk of influenza virus infection, hospitalization, and complication.)

When to Keep Your Child Home

Keep your child home from school or child care when he or she has a fever and other signs of the flu. Your child needs rest. Plus, your child might give the flu to other children.

Your child should stay home until at least 24 hours after the fever is gone. Start counting time after you stop giving your child fever medicines, such as acetaminophen or ibuprofen. A temperature of 100.4°F (38.0°C) or higher is a sign of fever. Check with your child’s school or child care center to find out its rules about children staying home when they are ill.

For the latest news about the flu, visit

Any websites, brand names, products, or manufacturers are mentioned for informational and identification purposes only and do not imply an endorsement by the American Academy of Pediatrics (AAP). The AAP is not responsible for the content of external resources. Information was current at the time of publication. The information contained in this publication should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.

© 2019 American Academy of Pediatrics. All rights reserved.

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