How the Flu Affects Babies and Young Children

Young toddler girl in bed

PhotoAlto / Anne-Sophie Bost / Getty Images

Babies and children under the age of two are at high risk for complications from the flu. When they get influenza, babies are more likely to get seriously ill and end up in the hospital than older kids.

Why Do Babies Get So Sick From the Flu?

Babies under the age of two are more likely to get the flu because their immune systems have not fully developed. They may also have difficulty feeding due to congestion, which can lead to dehydration. Productive coughing can be difficult for babies and pneumonia can develop quickly.

How the Flu Affects Your Child

Symptoms of the flu in babies include cough, congestion, fever, and fussiness. You should call your healthcare provider right away if your child:

  • Has difficulty feeding or refuses to drink
  • Is fussy or will not smile or play for more than 4 hours
  • Has difficulty breathing or makes a "whistling" sound (wheezing) when breathing
  • Has persistent vomiting or diarrhea
  • Has a frequent cough
  • Has a fever over 100.3 degrees (F) if under two months of age
  • Has no tears when they cry or has not had a wet diaper in 8 hours

These can all be signs of serious complications and should be discussed with your healthcare provider right away.

If your child does not have these serious signs but does have symptoms of the flu, call your healthcare provider during office hours. They may decide your child needs to be seen and tested for the flu. Antiviral medications (such as Tamiflu) may be necessary for your child to help minimize the chance for serious illness and complications.

If your child gets the flu, be sure to keep a close eye on them and watch for any changes. Babies may start out with a mild case of the flu but can get very sick quickly. If your child has been sick, seems to recover for a day or two and then suddenly gets sicker, call your healthcare provider. This is a sign of a secondary infection that could indicate bronchitis, pneumonia or another complication of the flu.

How to Protect Your Child From the Flu

Of course, better than treating the flu is preventing it altogether. Children over the age of six months should get a flu shot every year to prevent the flu. Single-dose flu vaccinations are now available, and can be requested. These are produced without thimerisol, which some research has indicated should be avoided in this vulnerable population.

Many parents have concerns about the safety and efficacy of flu shots for children. Many studies have been conducted and the results consistently show that the flu vaccine is safe and effective for children. There is no evidence that flu shots (or any other vaccine) cause medical problems such as autism and ADHD.

Babies under the age of six months cannot get a flu shot. However, there are still several ways you can protect them from the flu. If mom is pregnant during flu season, she should get the flu shot before the baby is born. The flu vaccine is safe for use during pregnancy and has been shown to protect the baby from the flu for up to six months after birth.

Breastfeeding is another great way to protect your baby from the flu. Breast milk contains antibodies which help strengthen your baby's immune system and provides protection while her body is developing.

In addition to the flu shot, everyday precautions can help protect your baby from the flu.

  • Wash your hands frequently
  • Keep your baby away from sick people
  • Be sure everyone who cares for your baby is vaccinated
  • Cover your cough (with your elbow or a tissue)

A Word From Verywell

The flu is a serious illness and can be very scary for a young child. Be sure to take the necessary steps to protect your baby from the flu and know the signs to watch for if they do get sick. If you have concerns or questions about your baby's health, consult your health care provider.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Havers FP, Campbell AJP. Influenza viruses. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th edition. Philadelphia: Elsevier; 2016.

  2. DeStefano F, Price CS, Weintraub ES. Increasing exposure to antibody-stimulating proteins and polysaccharides in vaccines is not associated with risk of autism. J Pediatr. 2013;163(2):561-7. doi:10.1016/j.jpeds.2013.02.001

  3. Centers for Disease Control and Prevention. Who Needs a Flu Vaccine and When. Updated October 11, 2019.

  4. Centers for Disease Control and Prevention. Influenza (Flu). Updated February 4, 2019.