Flu Symptoms in Babies and When to Call the Doctor

Unfortunately for worried parents, babies aren't immune to influenza. In fact, children under 5 years old—and especially those under 2—are actually more likely to suffer from flu-related complications like pneumonia and dehydration, according to the Centers for Disease Control and Prevention (CDC). Because the flu vaccine isn't recommended for those younger than 6 months old, it's important to recognize flu symptoms in babies and get proper treatment. Here's what you need to know.

Baby Flu Symptoms

In babies, influenza often resembles a bad cold with a high fever (and occasionally diarrhea or vomiting) that comes on quite suddenly. Babies with the flu are also fussy because they feel so awful, says pediatrician Luke Beno, M.D., with Kaiser Permanente in Atlanta.

According to March of Dimes, flu symptoms in babies include:

• Fatigue
• Cough
• Stuffy or runny nose
• Fever (at least 100 degrees F)
• Chills or shakes
• Sore throat
• Gastrointestinal issues like vomiting or diarrhea

Preventing Flu in Babies

Parents should take this respiratory infection seriously. Babies younger than 6 months have the highest risk of being hospitalized, as well as the highest rates of flu mortality. That's largely because their immune system hasn't fully developed and they're too young to have a flu shot.

If you were vaccinated during pregnancy, your antibodies cut your baby's flu risk by 41% during those first 6 months, according to research. "A flu shot given during pregnancy has been shown to not only protect the pregnant parent from flu, but also to help protect the baby from flu infection for several months after birth, before he or she is old enough to be vaccinated," says the CDC.

After 6 months, your child will be old enough for their own flu shot. Get the rest of the family and caregivers immunized too, advises Orlando pediatrician Hernando Cardona, M.D., of Windermere Pediatrics. One way your baby might contract the flu is if someone brings it home, he says.

The CDC takes the same stance. "As a caregiver to a young child, you should get a flu vaccine, and make sure that other caregivers and all household members aged 6 months and older also get vaccinated each year. By getting vaccinated, you will be less likely to get flu and therefore less likely to spread flu to the child," says the organization. "If the child you care for is 6 months or older, they should get a flu vaccine each year."

Also remember to take preventative measures against the flu. For example, wash your hands often, avoid contact with sick or unvaccinated individuals, and disinfect frequently touched surfaces.

When to Call the Doctor for Baby Flu Symptoms

If your little one spikes a fever, see your doctor that same day. A rapid test of nasal secretions can confirm that they have influenza. Your health care provider might administer an antiviral, such as Tamiflu, which can speed recovery and ward off complications. "When a baby is really sick, we'll give it, because the younger they are, the higher their risk for complications," says Dr. Cardona.

One of the most common flu complications is pneumonia, which develops when a flu virus migrates into the lungs from the nose and throat, or when a bacterial infection has cropped up. Viral pneumonia is treated with comfort measures; bacterial pneumonia requires antibiotics.

Also see your doctor right away if your baby has worrisome symptoms, including:

• Breathing difficulties
• Fast breathing
• High fever (or any fever in babies younger than 12 weeks)
• Bluish face or lips
• Chest pain
• Signs of dehydration
• Inability to wake
• Extreme fussiness
• Ribs pulling in while breathing
• Seizures
• Worsening of chronic health conditions
• Fever or cough that goes away, then returns and worsens

Is It Something Else?

The fall and winter months are full of viruses, from whooping cough to respiratory syncytial virus (RSV). Learn about the most common illnesses in babies that strike during flu season, and how to treat them:

• RSV in Infants: Everything Parents Need to Know
• All About Whooping Cough in Babies and Kids
• Bronchiolitis Symptoms and Treatment
• All About Croup in Babies and Toddlers
• Stages of a Cold in Babies
• COVID-19 in Babies: What Parents Need to Know About Symptoms and Transmission