COVID-19 Vaccines and Kids: What to Know

Medically Reviewed by Dan Brennan, MD on June 20, 2022

Since adults have made up most of cases of COVID-19, you may ask whether your child really needs one. In short, yes. Experts recommend that everyone 6 months old and older get a COVID-19 vaccination to protect against the coronavirus. While the original vaccines were developed for adults, thousands of health care provider offices, pharmacies, and health centers now also provide a pediatric version of the Pfizer COVID-19 vaccine and Moderna COVID-19 vaccine.

Doctors can’t always tell which children are more likely to become seriously ill from COVID-19. A vaccine will lower their chances of serious complications. Experts found that the vaccine was 90.7% effective in preventing COVID-19 in children aged 5-11. Now that vaccines are available to younger children, the Moderna and Pfizer COVID-19 vaccines can help more people. If younger people are vaccinated, it’ll also help protect older adults who are high risk.

Vaccine Trials for Children

After successful clinical trials, the FDA granted emergency use authorization of the Pfizer COVID-19 vaccines for those 6 months old and older. Children 6 months to 4 years old will get a third dose after at least 8 weeks from their second dose.

Children under the age of 5 will get three 3-microgram doses of the Pfizer COVID-19 vaccine. Kids ages 5-11 will receive two 10-micrograms doses. The vaccine for people 12 years old and older includes two 30-micrograms doses.

Experts studied the Pfizer vaccine’s safety in about 3,100 kids aged 5-11. The children received the COVID-19 vaccine and didn’t show any serious side effects. The FDA continues to collect and study data from children.

The FDA also updated the emergency use authorization for the Moderna COVID-19 vaccine. Now, those 6 months to 17 years old (in addition to people 18 and older) can get this vaccine.

Children under the age of 6 can get two 25-microgram doses of the Moderna COVID-19 vaccine. Those 6-12 years of age will get two 50-microgram doses. If you’re 12 years and older, you’ll receive two 100-microgram doses.

The Johnson & Johnson vaccine is for those 18 and older.

Experts suggest that all kids over the age of 5 years old get a booster shot. They can get it at least 5 months after their second dose of the COVID-19 vaccine.

Why Vaccines for Children Took Longer

Children weren’t a part of the original clinical trials because they’re generally not as vulnerable as adults. The majority of the deaths during the pandemic -- 92% -- have been people aged 55 and older.

This doesn’t mean that children are immune to COVID-19. They simply have a lower chance of serious complications from the virus.

Another reason that trials focused on adults first was speed. There are more levels of protection when children are involved in clinical trials. So it made sense to study an adult vaccine first to move quickly.

Scientists also needed more time to research children’s vaccines because their immune systems change fast. This means that a child’s body might respond differently to a vaccine depending on their age. It took experts longer to study these differences to make sure the vaccines were safe.

The CDC says adults can take the COVID-19 vaccine without regard to the timing of other vaccines. This means that you don’t have to wait a certain amount of time before you take another type of immunization, like experts previously thought. If you want to get the COVID-19 vaccine on the same day that you receive other vaccines, talk to your doctor first.

Similarly, the CDC Advisory Committee on Immunization Practices (ACIP) found that there’s no need for children aged 12-15 to wait between the COVID-19 vaccine and other vaccines. They can receive their routine immunizations at the same time as their COVID-19 vaccine.

We don’t yet know if children aged 5-11 can take a COVID-19 vaccine with another type of immunization.

Here’s what you can do in the meantime to keep your child safe, especially if they’re in a high-risk group:

  • Make sure everyone in your family gets a flu vaccine.
  • Make sure all eligible adults who spend time with your child get a COVID-19 vaccine.
  • Continue to practice social distancing, wear masks, and wash your hands often.

Side Effects of the COVID-19 Vaccine in Kids

The FDA says all known and potential benefits of the COVID-19 vaccine outweigh any known or potential risks.

Common side effects from the COVID-19 vaccine reported in clinical trials included:

  • Injection site pain or a sore arm
  • Redness and swelling
  • Fatigue
  • Headache
  • Muscle or joint pain
  • Chills
  • Fever
  • Swollen lymph nodes
  • Nausea
  • Lowered appetite

In a clinical trial for the Pfizer COVID-19 vaccine, side effects for children aged 6 to 23 months old included:

  • Irritability
  • Less of an appetite
  • Fever
  • Pain
  • Tenderness
  • Redness and swelling where the needle went in

In addition to these, some kids aged 2-4 also had headaches and chills after the Pfizer COVID-19 vaccine.

In a clinical study for the Moderna COVID-19 vaccine, experts found that the most common symptoms in children 6-36 months old included:

  • Irritability and crying
  • Sleepiness
  • Loss of appetite

In kids 37 months to 5 years old, experts found that the Moderna vaccine may cause:

  • Fatigue
  • Headache
  • Chills
  • Joint stiffness
  • Muscle aches
  • Nausea/vomiting

More kids showed side effects after the second dose compared to after the first. These symptoms tended to happen within 2 days after the vaccination and were mostly mild to moderately severe. Most of the side effects went away within 1-2 days.

Experts previously found that there was a higher risk of myocarditis (inflammation of your heart muscle) and pericarditis (inflammation of tissue surrounding your heart) after the Pfizer COVID-19 vaccine, specifically after the second dose.

Because of this, the FDA created a benefit-risk assessment to look at how many symptomatic COVID-19 cases, hospitalizations, people sent to the intensive care unit (ICU), and deaths that the COVID-19 vaccine would prevent in children 5-11 years old. They compared this to the number of potential myocarditis cases, hospitalizations, ICU admissions, and deaths that the vaccine might cause.

Their model predicts that the overall benefits of the vaccine outweigh any risks in children 5-11 years old.

Show Sources


Cincinnati Children’s Hospital: “Coronavirus (COVID-19) Information | Vaccines: What You Need to Know.”

American Academy of Pediatrics: “Moderna testing COVID-19 vaccine in children under 12,” “When can kids get the COVID vaccine or booster?”

Cleveland Clinic: “Why a COVID-19 Vaccine for Children May Take Longer.”

Rabia Agha, MD, director, Division of Pediatric Infectious Diseases, Maimonides Medical Center, New York City.

FDA: “COVID-19 Frequently Asked Questions,” “FDA Authorizes Pfizer-BioNTech COVID-19 Vaccine for Emergency Use in Children 5 through 11 Years of Age,” “Coronavirus (COVID-19) Update: FDA Authorizes Moderna and Pfizer-BioNTech COVID-19 Vaccines for Children Down to 6 Months of Age.”

CDC: "COVID-19 Vaccines for Children and Teens," “Interim Clinical Considerations for Use of COVID-19 Vaccines Currently Authorized in the United States,” “CDC Recommends Pediatric COVID-19 Vaccine for Children 5 to 11 Years.”

Michigan Health: “COVID Vaccines and Kids: 20 Things to Know.”

Yale Medicine: “COVID-19 Vaccines for Kids Under 5: What Parents Need To Know.”

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