Pediatric Vaccinations: What You Need to Know

Dr. Yadira Soler
Dr. Yadira Soler
August 17, 2022

It's been 18 months since COVID-19 vaccines were first approved for emergency use for adults. Parents of young children patiently waited while vaccines and boosters were approved for all other age groups. Kids ages 6 months to 5 years old, who have weaker immune systems because of their young age, haven't had the added protection of vaccinations, until now. The CDC now recommends COVID-19 vaccines for children as young as 6 months all the way up to 18 years old.

“Together, with science leading the charge, we have taken another important step forward in our nation’s fight against COVID-19,” said CDC Director Dr. Rochelle P. Walensky. “We know millions of parents and caregivers are eager to get their young children vaccinated, and with today’s decision, they can. I encourage parents and caregivers with questions to talk to their doctor, nurse, or local pharmacist to learn more about the benefits of vaccinations and the importance of protecting their children by getting them vaccinated.” 

As of June 2022, after lengthy trials, pediatric vaccinations for children 6 months to 5 years old are approved and rolling out. In fact, Nomi Health recently opened pediatric COVID-19 vaccination sites in several states. Many parents have questions about timing, side-effects, and generally what to expect for small children who receive the vaccine. We've put together a list of frequently asked questions to help you navigate COVID-19 immunization for your little ones.

Are vaccines safe for young children?  

Vaccines for children 6 months to 5 years of age were approved last of all the age groups because of the extensive testing and trials to ensure their safety. Side effects during both the Moderna and Pfizer clinical trials were minimal, and no myocarditis cases were reported in either clinical trial of this age group.  

COVID-19 vaccines are being monitored under the most comprehensive and intense vaccine safety monitoring program in U.S. history. CDC monitors all COVID-19 vaccines after they are authorized or approved for use. CDC and FDA will continue to monitor vaccines, keep people informed of findings, and use data to make COVID-19 vaccination recommendations.

“I think we have abundant clinical data from clinical trials from both the Moderna and the Pfizer vaccine that these vaccines are safe for children under five,” said Dr. Englund, a Professor of Pediatrics and Infectious Disease Specialist at Seattle Children’s. “They are also at a greatly reduced dose compared to the adult dosage of vaccine.”

Will my child have side effects from the vaccine? If so, what can I expect?  

There may be mild side effects from the vaccine. 1 in 4 Moderna recipients had a fever (which is typical of other young child vaccines).  

Generally mild pain at the injection site is a common occurrence for children who are between the ages of two and five.  

Fussiness and irritability for a day or two post-vaccine is another side effect one can anticipate but doesn’t happen for all kids.  

The CDC specifically notes these side effects can occur for children under 3:  

  • Pain where the shot was given
  • Swollen lymph nodes
  • Irritability or crying
  • Sleepiness
  • Loss of appetite

For children 4 years and older:  

  • Pain, swelling, and redness in the arm where the shot was given
  • Fever
  • Tiredness
  • Headache
  • Chills
  • Muscle or joint pain
  • Swollen lymph nodes

Which vaccine should my child get? Is one better than the other?

The AAP does not recommend one vaccine over the other. Both Pfizer and Moderna have been proven to be safe and effective. Parents should have their children vaccinated with either vaccine. Depending on the vaccine product, your baby or young child will need two or three doses. Most parents should get whichever vaccine is most available to them. In some instances, they may have only one option. This also is common for other types of childhood vaccines in which there are multiple manufacturers.

The Pfizer vaccine is currently a 3-dose series and the Moderna is a 2-dose series. The two vaccines use different amounts of mRNA and have other differences in composition. Parents should not choose the vaccine for their child based on the number of doses, because they may be the same number in the end.

  • The 3-dose vaccine (Pfizer) was first tested using 2 doses. Adding the third dose was found to be more effective at protecting babies and young children from the omicron variant. The vaccine is a 3-dose series.
  • The 2-dose vaccine (Moderna) was tested using 2 doses. They were found to be safe and effective. Right now, Moderna is studying a third dose of their vaccine. It is possible that the vaccine also may turn into a 3-dose series.

How effective is the vaccine?  

Children will have the highest degree of protection two weeks after they get the last required dose.

According to the Mayo Clinic, to determine the effectiveness of the Pfizer-BioNTech vaccine for kids ages 6 months through 4 and the Moderna COVID-19 vaccine for kids ages 6 months through 17 years old, the FDA looked at the immune responses of children in these age groups after they were fully vaccinated. The FDA compared those responses to the immune responses of young adults who’d been given higher doses of the same mRNA vaccine.


In this analysis, among participants 6 through 23 months of age, 64% of whom had blinded follow-up for more than two months after the second dose, the vaccine was 50.6% effective in preventing COVID-19. Among participants 2 through 5 years of age, 72% of whom had blinded follow-up for more than two months after the second dose, the vaccine was 36.8% effective in preventing COVID-19.


For the three-dose Pfizer vaccine, the vaccine effectiveness was 80.3%, but that number was based on a small number of children so it could be lower or higher than this. As with older kids, we expect that these vaccines will do a better job of preventing severe disease than they do preventing mild disease.

If you have further questions or would like more information about where you can get a COVID-19 vaccine for your child, reach out to your pediatrician's office for guidance on local vaccination sites.