Medical Conditions


Seasonal Influenza (Flu)

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What is 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 per season and many times in their lives. Influenza viruses are unpredictable. They are always changing over time and from year to year.

Read on for more information from the American Academy of Pediatrics about signs of the flu, how to prevent the flu, how to prevent flu germs from spreading, and what to do if your child gets the flu.

Signs of the flu

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

  • A sudden fever (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 and have diarrhea. Talk with your child's doctor if your child has ear pain, a cough that will not go away, or a fever that will not go away. There can be serious complications, even death, from the flu, but these are uncommon.

How to prevent the flu

Get the flu vaccine every year. Safe vaccines are made each year to protect against the flu. Everyone should get the vaccine as soon as it is on hand in your community.

Two types of influenza vaccines are available in the United States for the 2016–2017 season according to the number of influenza virus strains they contain: trivalent (3 strains) and quadrivalent (4 strains) inactivated influenza (IIV) vaccines. One flu vaccine is not preferred over another.

The inactivated vaccine is given as an intramuscular (into the muscle) shot, and it is licensed and recommended for infants and children 6 months and older and adults, including people with and without chronic medical conditions. The intradermal (into the skin) shot is licensed for use only in people 18 through 64 years of age. Live-attenuated influenza vaccine (LAIV) is not recommended for use during the 2016–2017 season.

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

  • Influenza vaccines are not licensed 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 received fewer than 2 doses of flu vaccine before July 1, 2016. This includes children who have received either the intranasal or intramuscular flu vaccine in the past and children getting the flu vaccine for the first time.

    • Need only 1 dose if they received 2 or more doses of flu vaccine before July 1, 2016. This includes children who have received either the intranasal or intramuscular flu vaccine in the past, in the same or more than one season.

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

  • Optimal protection from the flu vaccine lasts for only about 6 to 12 months.

  • The virus strains in the vaccine often change.

Vaccination is especially important for

  • All children, including infants born preterm, who are 6 months old to 5 years of age

  • Children with conditions that increase the risk of complications from the flu

  • Children of American Indian or Alaska Native heritage

  • All household contacts and out-of-home care professionals of children with high-risk conditions and of 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

Does the flu vaccine have any side effects?

The flu vaccine has very few side effects. The area into which the IIV flu shot is given may be sore for 1 or 2 days. Fever may occur within 24 hours 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. This is why it is important to receive the vaccine before the flu season starts.

Is the flu vaccine safe for children with egg allergies?

Children with a history of egg allergies, such as hives, can get the flu vaccine safely at their doctor’s office, because the risk of having anaphylaxis (a serious allergic reaction) from the flu vaccine is extremely low. They should be observed in the office after getting the vaccine, as routinely done for all vaccines. Check with the doctor if you have any questions.

When should my child get the flu vaccine?

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

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 with 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. That is 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, nose, or mouth.

  • Teach your children to cover their mouth and nose 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.

What if my child gets the flu?

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

  • Asthma, diabetes, 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 (being very overweight)

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

  • Is 3 months or younger and has a fever

  • Has fast breathing or trouble breathing

  • Looks very sick

  • Is sleepier than usual

  • Is very fussy no matter what you do

  • Cannot or will not drink anything

  • Urinates very little

  • Has blue skin color

  • Will not wake up at all or is inconsolable

Drugs to treat the flu

The doctor may be able to treat the flu with a medicine. These drugs work best against the virus when your child gets them within the first 1 to 2 days of showing signs of the 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, such as asthma, diabetes, sickle cell disease, or cerebral palsy

  • Is younger than 6 months

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

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 has any aches or pain.

  • For a baby 6 months or younger, give acetaminophen. Tylenol is one brand of acetaminophen.

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

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

Keep your child home

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

When can my child go back to school or child care?

Your child should stay home until at least 24 hours after his 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°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

Listing of resources does 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.