Babies under 6 months are at the highest risk overall because the flu vaccine cannot be used in them safely.
This article will describe the signs and symptoms of flu in babies and toddlers so that you know when it’s time to seek immediate medical care. It will also offer tips on how to prevent the flu, including the right time to get a flu shot.
What Causes the Flu?
Influenza (flu) is a highly contagious respiratory infection caused by the influenza virus. The virus is mainly passed through respiratory droplets created when people with flu cough, sneeze, or talk. The bulk of infections happen during “flu season” (roughly October through March) but can occur any time of the year.
Because the virus has many strains, each of which rapidly mutates, you can get flu year after year and even more than once a year. You are never immune to the virus.
With that said, you can greatly reduce your risk by receiving the annual flu vaccine, which changes every year based on which strains are most likely to circulate. But even with a flu shot, you can still get the flu, although generally less severely.
Why Young Children Are at a Greater Risk
According to the Centers for Disease Control and Prevention (CDC), children under 5 years of age—and especially those under 2—are at higher risk of developing serious flu-related illnesses than older children and adults.
This is because their immune systems have not yet developed a defensive response to the virus in the form of antibodies. Antibodies are proteins produced by the immune system that target disease-causing organisms like the flu virus for destruction.
While no one is ever fully immune to the flu (because it is constantly changing), with every infection your body “remembers” the virus and creates longer-lasting antibodies to trigger a response should it return.
Because babies and toddlers have not developed these defenses, they are more vulnerable to severe infections and potentially life-threatening complications like:
Pneumonia: An infection of the air sacs of the lung Encephalopathy: A brain complication caused by persistent high fever Myocarditis: Inflammation of the heart Severe dehydration: Due to high fevers that deplete the body of water Sepsis: The severe overreaction of the immune system to an infection
On rare occasions, these and other complications can cause death.
Flu Signs and Symptoms in Babies
The flu can rapidly turn serious in babies in part because they cannot tell you what they feel. They may be fussy or experience symptoms you assume are related to the common cold. Even among toddlers who can speak, the symptoms are often very different from those in adults.
Call your healthcare provider if your baby has the following signs and symptoms of the flu:
Fever over 100 FFrequent coughRunny or stuffy nosePersistent fatigue (tiredness)Vomiting or diarrheaDifficulty feeding or refusing to drinkPersistent fussiness and unwillingness to play or smile
Even if you’re not sure what you are dealing with, it’s best to play it safe and speak with a healthcare provider. If they are not available, try a telehealth service or a walk-in clinic near you.
When to Go to the Emergency Room
If your child has the flu, it is important to recognize the signs and symptoms of a medical emergency. Call 911 or go to the nearest emergency department if your child experiences:
Shortness of breath or wheezing Severe lethargy or difficulty waking up Persistent vomiting Severe diarrhea Lack of tears with crying Lack of urination or wet diapers for eight hours Blue lips or skin Fever over 100 F for infants 3 months or younger Return of fever and flu symptoms after they’ve gone away Seizures or convulsions
Diagnosis and Treatment
The diagnosis of flu in babies and toddlers is based on observation and a review of the child’s symptoms. Nothing else is needed to confirm the diagnosis.
Other tests may be ordered if there are signs of complications such as pneumonia, encephalopathy, myocarditis, or sepsis, These may include blood tests, X-rays or other imaging studies, or an electrocardiogram (ECG) to measure the electrical activity of the heart.
Your healthcare may prescribe antiviral medications that can shorten the length and severity of the flu (and may even help prevent pneumonia). These are most effective when started within two days of the first signs of the flu.
In the United States, there are three antivirals approved for use in treating flu in children:
Tamiflu (oseltamivir): Available as a capsule or liquid for children 2 weeks and over Rapivab (peramivir): Delivered intravenously (into a vein) for children 2 years and over Relenza (zanamivir): Delivered in inhaled powder form for children 5 years and over
What Parents Can Do to Prevent the Flu
Preventing the flu in children is a far better option than treating it. Central to this is annual flu vaccination starting at 6 months of age.
There are two flu vaccine options currently available for children:
Flu shots: Delivered by injection into the upper arm or thigh and approved for children 6 months and over FluMist: An inhaled nasal vaccine approved for children 2 years and over
The CDC recommends that children receive the vaccine every year around the end of October. Children between the ages of 6 months and 8 years should get two doses if they have not been vaccinated before. Thereafter, they only need one dose.
Flu Prevention in Newborns
Babies under 6 months cannot get the flu shot. This is because their immune systems are too underdeveloped and may react adversely to the vaccine.
However, there are still several ways to protect them from the flu:
Maternal vaccination: People who are pregnant during flu season should get the flu shot before their baby is born. The flu vaccine is safe during pregnancy and has been shown to protect the baby from the flu for up to 6 months after birth. Breastfeeding: Breast milk contains antibodies that help strengthen your baby’s immune system. This includes antibodies produced in response to the flu vaccine.
Summary
Children under 5 years of age, and especially those under 2, are at increased risk of complications from the flu (influenza), including pneumonia, myocarditis, and sepsis. To avoid this, it is important to recognize the signs and symptoms in babies and young children, including fatigue, fever, cough, poor feeding, persistent fussiness, vomiting, and diarrhea.
Wash your hands frequently. Keep your baby away from sick people. Be sure that everyone who cares for your baby is vaccinated. Cover your cough with your elbow or a tissue.
You can help prevent the flu by getting your child vaccinated every year starting at 6 months of age. Children 6 months and over can get the flu shot. Those 2 years and over can receive the nasal flu vaccine.
A Word From Verywell
Severe illnesses and rare cases of death from flu mainly occur in unvaccinated children. Despite what some people may tell you, the flu vaccine is safe and is in no way linked to autism, ADHD, or any other medical condition.
When it comes to babies and toddlers who have not yet developed the immune defenses to avoid severe infections, the benefits of annual flu shots far outweigh any risks, real or presumed.
