Flu Shots for Kids: Why Your Child Needs One Every Fall

Every child 6 months and older should get a flu vaccine every fall. The flu changes from year to year, protection fades over time, and young children are among the most likely to land in the hospital with flu complications. A yearly flu shot is the simplest way to keep your child healthy, in school, and out of the emergency room this winter.

At The Pediatric Group, we've been caring for children in Princeton and across Mercer and Somerset counties for decades. Each fall, parents ask us the same thoughtful questions about the flu shot. Here are our answers, based on the latest guidance from the American Academy of Pediatrics (AAP).

Why does my child need a new flu vaccine every year?

Your child needs a new flu vaccine each year because flu viruses keep changing, and the protection from last year's shot wears off.



Think of the flu virus like a child who keeps outgrowing their shoes. Every season, small changes in the virus mean last year's "fit" no longer matches. Scientists track which strains are spreading around the world and update the vaccine to match the strains most likely to circulate. For the 2026–27 season, every flu vaccine in the U.S. protects against three strains, and those strains were updated for this year.

There's a second reason, too. Even when the strains stay similar, the immune protection a flu shot provides fades over the months that follow. A fresh dose each fall gives your child strong protection for the season ahead, which in New Jersey usually peaks between December and February.

Why are young children at higher risk from the flu?

Children under 5, and especially those under 2, are more likely to develop serious flu complications because their immune systems are still learning to fight new infections.

For an adult, the flu might mean a miserable week on the couch. For a toddler, it can turn serious quickly. Young children have small airways that clog easily. They can become dehydrated fast when fever keeps them from eating and drinking. And they can't always tell you how sick they feel.

Flu complications we see in young children include:

• Pneumonia and other lung infections
• Ear and sinus infections
• Dehydration
• Worsening of asthma or other chronic conditions
• Febrile seizures caused by high fever
• Rarely, inflammation of the heart, brain, or muscles

Children with asthma, diabetes, heart disease, or neurological conditions face even higher risk. But many children who are hospitalized with the flu were perfectly healthy beforehand. That's why we recommend the flu vaccine for every child 6 months and older, not just those with medical conditions.



Vaccinating your child also helps protect the people around them. That includes newborn siblings too young to be vaccinated, grandparents, and classmates with weakened immune systems.

Why do some children under 9 need two flu shots?

Children 6 months through 8 years old who have never had at least two flu vaccine doses before July 1 of this year need two doses this season, given at least four weeks apart.

Here's why. A child's very first exposure to the flu vaccine works like a warm-up. It introduces the immune system to the flu. The second dose, a month later, builds on that introduction and creates much stronger protection. After that first season, one dose a year is enough.

Your child likely needs two doses this fall if:

• They are getting a flu vaccine for the first time, or
• They are under 9 and have received only one flu vaccine dose in their life

Not sure about your child's history? That's what we're here for. We keep your child's immunization records and will let you know at the visit whether a second dose is needed. Children who need two doses should start as early in the fall as possible, so both doses are done before flu season takes off..

Can the flu shot give my child the flu? (And other common myths)

No, the flu shot cannot give your child the flu. The flu shot contains either inactivated virus or a single protein from the virus, neither of which can cause an infection.

We hear a handful of flu shot myths every fall. Here's the truth behind each one.

Myth: "My child got the flu shot last year and still got sick." Fall and winter bring dozens of viruses that cause colds, coughs, and fevers, and the flu shot only protects against the flu. It also takes about two weeks after vaccination for protection to build. And even when a vaccinated child does catch the flu, the illness is usually milder and far less likely to lead to a hospital stay.

Myth: "My child is healthy, so they don't need it." Healthy children get seriously ill from the flu every year. Many children hospitalized with the flu had no underlying medical conditions.

Myth: "The flu is just a bad cold." A cold usually comes on gradually and stays mild. The flu often hits suddenly, with high fever, body aches, and exhaustion that can keep a child home for a week or more.

Myth: "It's better to build natural immunity." Getting the flu to become immune means risking the very complications the vaccine prevents. And because the virus changes every year, natural immunity from a past infection won't fully protect your child this season.

What side effects should I expect after my child's flu shot?

Most children have no side effects or only mild ones that go away within a day or two.

Common, mild reactions include:

• Soreness, redness, or swelling where the shot was given
• A low-grade fever
• Mild body aches or tiredness
• Fussiness in babies and toddlers

These are signs the immune system is doing its job, not signs of the flu. A cool compress on the arm or leg, extra fluids, and some cuddle time usually help. Ask us about the right dose of a fever reducer for your child's weight, or check the Medicine Dosages page on our website.

Serious reactions are rare. In young children, a fever after vaccination can occasionally trigger a brief febrile seizure. Call 911 right away if your child has trouble breathing, swelling of the face or throat, or hives soon after a vaccine. For anything else that worries you, call our office.

Is your child nervous about shots? Millie, our licensed therapy dog, visits the office on Tuesdays to help anxious kids feel calmer during shots and blood draws.

When should my child get a flu shot, and where?

The best time to get your child's flu shot is now, as early in the fall as the vaccine is available, and ideally by the end of October.

With federal vaccine guidance in flux this year, you may have seen confusing headlines. Our commitment hasn't changed. The Pediatric Group continues to recommend vaccines based on the best available scientific evidence, and we follow the AAP's recommendation of a yearly flu vaccine for every child 6 months and older.

Schedule your child's flu shot with The Pediatric Group this fall:

• Call us: 609-924-4892
• Book online: Use the Appointments page on our website
• Message us: Through the Patient Portal
• Visit us: 281 Witherspoon Street, Suite 200, Princeton, NJ 08540

Coming in for a well visit soon? Ask about adding a flu shot at the same appointment. And while you're here, ask whether siblings are due, too.

Protecting the whole family is one of the best gifts you can give each other this winter.

Sources

• AAP news release: Recommendations for influenza prevention and control, 2026–27
• HealthyChildren.org: AAP flu recommendations for 2026–27
• Contemporary Pediatrics: AAP 2026–2027 influenza updates
• Advocare The Pediatric Group homepage