Most parents know their child should get a flu shot every year. But what many don’t realize is that some children need two flu shots during the same influenza season to get the best protection.
While everyone older than 6 months should get a flu vaccine each year, children between 6 months and 8 years old often need two doses to be fully protected. We talked with Nathan Price, MD, a pediatric infectious disease specialist with Banner - University Medicine, to find out if your child might benefit from two flu shots this year.
Why do some children need two flu shots?
Annual flu vaccination is recommended for everyone 6 months and older. For most children who’ve been vaccinated against flu before, a single dose each season is enough. But some children aged 6 months through 8 years may need two doses and here’s why:
“Young children don’t respond as well to a single dose of flu vaccine the first time they get vaccinated for flu,” Dr. Price said. “They need a second dose to boost their immune system enough to develop the protection they need.”
Your child may need two doses if they:
- Are getting flu vaccine for the first time
- Have only received one flu vaccine dose before
- Have an unknown flu vaccination history
Once your child’s immune system has been “introduced” to the vaccine with two properly timed doses, they’re usually considered primed. In future flu seasons, they’ll typically only need one annual flu shot.
If your child has already received the recommended number of flu vaccine doses in previous seasons, they’ll likely only need one flu shot this year.
Learn more about pediatric vaccinations and immunizations.
What if your child’s flu vaccine records aren’t clear?
If you've moved, changed pediatricians or can't remember your child's flu shot history, ask your child's provider to check your state's immunization information system. It keeps track of vaccinations from different health care providers and pharmacies.
If the records aren't clear, the usual plan for children aged 6 months to 8 years is to give two doses this season. Getting an extra dose is safe and it's better to ensure your child is fully vaccinated rather than leaving gaps in their protection.
When you're unsure, your child's provider is the best resource to help clarify the vaccination history, especially if your child has other health conditions.
When should children get their two flu doses?
If your child needs two doses of the flu vaccine, waiting until flu season is in full swing might leave them unprotected. Health experts recommend getting vaccinated before flu season begins.
“It takes about one to two weeks after vaccination for the immune system to build protection," Dr. Price said. "For young children who need two doses, this protection doesn’t develop until one or two weeks after the second shot."
The two doses should be given at least four weeks apart. Giving the first dose early gives your child enough time to finish the series before flu viruses spread widely.
“Flu can spread all year, but the highest risk of widespread outbreak is in fall and winter," Dr. Price said. “The flu vaccine is usually available just before flu season starts in the fall. It’s best to get the shot early so you’re protected when the virus starts spreading."
What if the second dose is delayed?
Life happens. Kids get sick, schedules fill up and appointments get missed. The good news is your child doesn't need to start over if more than four weeks have passed. But delaying the second dose also delays your child’s full protection.
"If the second dose is late, your child remains unprotected until one or two weeks after that second dose,” Dr. Price said. “It's best to give the second dose as close to four weeks after the first dose as possible. If more than four weeks have passed, it's still important to get the second dose as soon as you can."
What about babies younger than 6 months?
The flu vaccine is not approved for babies under 6 months old, so they depend on the people around them for protection.
Here are some ways you can protect your baby who can’t get vaccinated:
- Have everyone living with or caring for your baby get their annual flu shot.
- If you are pregnant, get vaccinated to protect both yourself and your baby during the first few months.
- Wash your hands often.
- Cover coughs and sneezes.
- Keep sick people away from your baby when possible.
If your baby is exposed to the flu, talk to their doctor or health care provider. In some cases, antiviral medication may be recommended after exposure.
Are there times a child should wait to get vaccinated?
Most children can safely get a flu vaccine every year.
Talk to the doctor if your child:
- Had a severe allergic reaction to a previous flu vaccine or its ingredients
- Is moderately or very sick on the day of the appointment
- Has a complex health condition or if you're unsure which flu vaccine is right for them
Together, you can choose the safest plan for your child's vaccination.
Bottom line
Most children only need one flu shot. However, children ages 6 months to 8 years may need two doses to get the best protection against the flu.
If your child needs two doses:
- Give the first dose early in the flu season.
- Schedule the second dose for at least four weeks after the first.
- If the second dose is delayed, get it as soon as possible. You don't have to start over.
- If you're not sure about your child's vaccination history, ask their health care provider.
A little planning now can help your child stay protected before flu season reaches its peak.
Flu shots are available at many locations, including Banner primary care, Banner Urgent Care, pharmacies and clinics. Find a Banner location near you.
FAQs
How can I tell if my child needs one or two flu shots?
Some children aged 6 months through 8 years need two doses if they are getting a flu vaccine for the first time, have only had one flu shot before or if their vaccination history is unknown. Your child's health care provider can help decide what is best.
Why do some children need two flu shots?
The first shot helps the immune system learn about the vaccine. The second shot boosts the immune response so younger children can build better protection against the flu.
How long should I wait between the two flu shots?
Children who need two doses should get the second one at least four weeks after the first shot.
What if my child's second flu shot is late?
Your child doesn’t need to start over. Just give the second dose as soon as you can so they get full protection.
Can babies younger than 6 months get a flu shot?
No. Babies younger than 6 months are too young for the flu vaccine. The best protection is from vaccination during pregnancy and making sure parents, caregivers and close contacts get the shot every year.
Should my child get a flu shot even if they had the flu last year?
Yes. The flu virus changes each year, so everyone 6 months and older should get a new flu vaccine every year.
