The COVID-19 Vaccine in Young Kids: What to Know

The U.S. Food and Drug Administration (FDA) has authorized COVID-19 vaccines for young children. Children 6 months old and up can receive either the Moderna or Pfizer-BioNTech vaccine.

For the first time in the U.S., children under 5 can get vaccinated against COVID-19. About 18 million U.S. children now are eligible for the first time.

The Centers for Disease Control and Prevention (CDC) recommends vaccination for kids 6 months and up.

Here’s what you need to know about vaccines for young children.

Why Do Young Kids Need the COVID-19 Vaccine?

Vaccination is the best way to prevent COVID-19 — and, in turn, prevent severe illness, hospitalization, and death.

Children under age 5 represent about 3% of all COVID-19 cases in the United States. But children under 5 have higher hospitalization and death rates than children of other ages.

In March 2022, the CDC released a report detailing hospitalization rates in children ages 0 to 4 after the Omicron (B.1.1.529) variant began circulating in the U.S. in December 2021.

According to the report, hospitalization rates for children 0 to 4 were five times higher during Omicron than they were when the Delta variant (B.1.617.2) was the dominant variant.

Children with underlying conditions like congenital heart disease, asthma or lung disease, diabetes, obesity, or compromised immune systems are at high risk for COVID-19 complications. But even kids without other health conditions are at risk. Vaccination can help lower their risk. Young children are capable of becoming infected and infecting higher-risk family members, such as elderly or immunocompromised people.

Getting the COVID-19 vaccine also can lower your child’s risk of developing multisystem inflammatory syndrome in children (MIS-C). MIS-C is a rare but serious complication of COVID-19 that can cause inflammation of the skin, eyes, or in several different internal organs.

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Does the COVID-19 Vaccine Work in Young Kids?

Before authorizing the vaccines, the FDA released data on their effectiveness from clinical studies.

According to the data:

  • Both the Moderna and Pfizer vaccines are safe in young children, with the most common side effect being fever, fatigue, or pain at the site of injection. Each brand of vaccination induced immune responses in young children similar to those seen in older children or young adults. The primary series for Moderna is two injections, four weeks apart. The primary series for Pfizer is three injections over a period of 12 weeks.

The data for efficacy is difficult to compare to prior vaccine releases. That’s because the circulating variant at the time of the study (Omicron) was more contagious than prior variants.

The values on efficacy for both vaccines may change with a larger sample size and different circulating variants. Both vaccines met the FDA’s efficacy standards for authorizing them. The vaccines are likely even more effective in preventing severe outcomes like hospitalization and death.

Is the COVID-19 Vaccine Safe for Young Kids?

Both trials reported the vaccine was safe for young children, with some common minor side effects. Those side effects included:

  • Injection site pain, redness, or swelling.
  • Fever.
  • Headache.
  • Fatigue.
  • Irritability or crying.

Some side effects, like fever, were more prevalent in certain age groups. Most side effects were mild to moderate and went away within one to two days.

There were no reported cases of myocarditis or pericarditis during the clinical trials. These heart conditions have been a rare complication of the mRNA vaccines in some age groups, particularly young men.

The vaccines are safe for children.

How Big Will the Vaccine Doses Be for Young Kids?

Both the Pfizer and Moderna vaccine doses will be smaller for younger children.

  • Pfizer: Each dose of the Pfizer vaccine for children under 5 will be one-tenth of the size of Pfizer’s adult dose. Children under 5 will receive two doses, at least three weeks apart, followed by a third dose at least two months later.
  • Moderna: Each dose of the Moderna vaccine for children under 6 will be one-quarter the size of Moderna’s adult dose. Children under 6 will receive two doses, scheduled at least four weeks apart.

When Will the Vaccine Be Available for Young Kids?

The CDC officially recommended the vaccine in young kids on June 18, 2022. That opened the door for vaccination to begin throughout the country during the week of June 20.

If you wish to schedule a vaccine appointment at UPMC for your child, you can take the following steps:

  • If your child or patient is an existing UPMC Children’s Community Pediatrics patient, schedule an appointment through the UPMC Children’s Community Pediatrics website or by calling the child’s pediatrician’s office.
  • If your child or patient is NOT an existing UPMC Children’s Community Pediatrics patient, you can schedule an appointment on our website by using the “Schedule a COVID-19 Vaccine” button. Or, you can call 844-876-2822 between 8 a.m. and 5 p.m., Monday through Friday.

Editor's Note: This article was originally published on , and was last reviewed on .

Centers for Disease Control and Prevention, Morbidity and Mortality Weekly Report, Hospitalization of Infants and Children Aged 0–4 Years with Laboratory-Confirmed COVID-19 — COVID-NET, 14 States, March 2020–February 2022. Link

Centers for Disease Control and Prevention, People with Certain Medical Conditions. Link

Centers for Disease Control and Prevention, Why Children and Teens Should Get Vaccinated Against COVID-19. Link

Sharon LaFraniere, New York Times, Moderna's Covid Vaccine Is Effective in Children Under 6, F.D.A. Says. Link

Sharon LaFraniere, New York Times, Pfizer Vaccine Effective in Children Under 5, the F.D.A. Says. Link

Matthew Perrone and Mike Stobbe, Associated Press, U.S.: Pfizer COVID-19 Vaccine Appears Effective for Kids Under 5. Link

U.S. Food and Drug Administration, FDA Briefing Document, EUA Amendment Request for Pfizer-BioNTech COVID-19 Vaccine for Use in Children 6 Months Through 4 Years of Age. Link

U.S. Food and Drug Administration, FDA Briefing Document, EUA Amendment Request for Moderna COVID-19 Vaccine for Use in Children 6 Months Through 17 Years of Age. Link

About UPMC

Headquartered in Pittsburgh, UPMC is a world-renowned health care provider and insurer. We operate 40 hospitals and 800 doctors’ offices and outpatient centers, with locations throughout Pennsylvania, Maryland, New York, West Virginia, and internationally. We employ 4,900 physicians, and we are leaders in clinical care, groundbreaking research, and treatment breakthroughs. U.S. News & World Report consistently ranks UPMC Presbyterian Shadyside as one of the nation’s best hospitals in many specialties and ranks UPMC Children’s Hospital of Pittsburgh on its Honor Roll of America’s Best Children’s Hospitals. We are dedicated to providing Life Changing Medicine to our communities.