Influenza (seasonal flu)

What is the flu? 

A contagious respiratory illness caused by any of several strains of influenza (flu) virus, seasonal flu primarily affects the nose, throat, and lungs. A person’s illness with the flu can range from mild to severe to fatal. The duration of the flu season, as well as the severity of the flu virus, varies from one year to the next. Flu outbreaks begin as early as October and typically peak in January, although they last through March or April. That’s why the CDC encourages people to get a flu shot as soon as it is available, usually in September or early October. 

What are flu symptoms? 

Symptoms of the flu are similar to many other illnesses, including the common cold and COVID-19. These include: 

  • fever or sense of being feverish 
  • chills 
  • cough 
  • sore throat 
  • runny or stuffy nose 
  • muscle or body aches 
  • headache 
  • fatigue 

Children may be more likely to have a fever of 101 degrees Fahrenheit or higher, and they may also have vomiting and/or diarrhea. 

Typically, symptoms are more intense than those experienced with the common cold and can lead to severe complications such as pneumonia, bronchitis, ear infections, sinus infections, and dehydration. Children younger than 5 years of age and those with chronic health conditions such as asthma and diabetes are at increased risk of complications.

How do children get the flu? 

Unfortunately, this highly contagious disease can spread rapidly, especially among children. Although children can get the flu by touching an object that has the virus on it and then touching their mouths or noses, the typical mode of transmission is contact with contaminated droplets spread when an infected person sneezes or coughs. These droplets can travel up to six feet away from the sick person.

A person with the flu virus can spread the illness even before they realize they are sick. Transmission can occur as much as one day before the onset of symptoms, and the affected person remains contagious for up to 5 to 7 days after becoming sick. Children, and others with weaker immune systems, are thought to be contagious for an even longer period of time. 

What is the influenza vaccine? 

The best offense against the flu is a good defense. The influenza vaccine developed prior to the onset of each flu season is tailored to fight the specific strains of illness experts believe will be prevalent during that season. Since the flu vaccine takes about two weeks to reach full effect, it's best to get vaccinated as soon as that season's vaccine becomes available, generally around September-October. The CDC cautions against getting vaccinated too early, in July or August, as this may lead to reduced protection against influenza later in the season.

According to the CDC, it's important to remember that the flu vaccine contains three or four flu viruses (depending on the type of vaccine you receive) so that even when there is a less than ideal match or lower effectiveness against one virus, the flu vaccine may protect against the other flu viruses. For the 2022-23 flu season, flu vaccines for will be available in injectable and nasal spray forms. Consult your child's health care provider to decide which one is best for them.

How can the flu be prevented? 

The CDC recommends that everyone 6 months of age and older, who is eligible, receive a yearly influenza vaccine as the first and most important step to protecting against flu viruses. Infants younger than 6 months are too young to be vaccinated and at greater risk for flu complications. Therefore, parents, siblings, and other caregivers who are eligible for the vaccine should be vaccinated at the start of flu season, to reduce infants’ risk of contracting the flu.

The CDC recommends

  • For everyone 6 months and older: Get vaccinated for the flu, each and every year.
  • For children ages 6 months to 8 years old who have received fewer than 2 doses of flu vaccine ever: Two doses of vaccine should be given, with at least a 4 week interval between the 2 doses. For best protection from the flu, the first dose should be given as soon as the vaccine becomes available.
  • For children with a history of egg allergy, flu vaccination is okay. There is no need for medical observation during the 30 minutes post-vaccine. But children with severe egg allergy (symptoms other than hives, including respiratory distress or anaphylaxis) should have their vaccine given by a health care provider who is able to recognize and manage severe allergic reactions.

While the flu vaccine provides good protection, it does not eliminate all risk. Especially during cold and flu season, follow practices of good hygiene to stay healthy:

  • All family members should wash their hands often (when returning home, after using the bathroom or changing a diaper, after using a tissue, before eating or preparing food). Use soap, warm water, and plenty of friction for at least 20 seconds (equal to a couple of verses of “Twinkle, Twinkle Little Star”). 
  • Disinfect common surfaces (doorknobs, light switches, faucet handles) and change hand towels regularly
  • Avoid contact with people who are sick, and stay away from others if you develop symptoms. A child with the flu should be kept home (except to seek medical care) until he has been fever-free for at least 24 hours (without using a fever reducing medication , such as ibuprofen or acetaminophen). 
  • Don’t share food or drink.
  • Cover your mouth or nose during coughing or sneezing. If a tissue is not handy, use your elbow or the back of your forearm to catch the germs. If a tissue is handy, discard it immediately and wash your hands. 
  • Keep your hands away from your face.

How is the flu treated?

If you do come down with the flu, doctors can prescribe antiviral drugs to combat the virus. These medicines keep flu viruses from reproducing in the body, ease symptoms, shorten the duration of illness, and prevent serious complications.

While most healthy adults who contract the flu will not need antiviral drugs during the course of their illness, antiviral drugs are recommended for:

  • children under 5 years old (and especially under age 2)
  • children with underlying medical conditions such as asthma
  • anyone who is at greater risk for developing severe flu-related complications
  • pregnant women and those who have delivered a baby within the previous two weeks of contracting the flu

Whether or not they receive antiviral medication, children with the flu should get plenty of rest and drink lots of fluids. Children who are breastfeeding should continue to do so. Acetaminophen or ibuprofen can be given to manage fever, aches, and pains; the child’s pediatrician can provide information about the best medication and appropriate dose (which is best based on the child's weight). 

When should I call a doctor? 

Because children younger than 5 years old are at high risk for developing flu-related complications such as pneumonia, bronchitis, ear infections, sinus infections, and dehydration, parents should talk to their child’s health care provider immediately if their child has flu-like symptoms. (Note that children younger than 2 are at the greatest risk.)

Parents should seek immediate medical care for their child if the child displays any of the following emergency warning signs

  • fast breathing or trouble breathing 
  • bluish skin color 
  • refusal of fluids 
  • extreme drowsiness or listlessness 
  • irritability 
  • skin rash 

Infants who display any of the above symptoms or are unable to eat, don’t produce tears when crying, or have significantly fewer wet diapers than usual, should be taken to the emergency room immediately. 

Last updated March 15, 2023

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