What You Need to Know About the COVID-19 Vaccine for Children

Stock photo of young girl receiving a shot

Now that children as young as 5 are eligible to receive the Pfizer COVID-19 vaccine, many parents and guardians have questions.

As a mother of three children, Margaret Day, MD, understands the need for information. And with her background as a family medicine doctor and vaccine expert, she can share the answers.

Margaret Day, MD
Margaret Day, MD

Is the vaccine safe for children?

Yes. "The vaccines for COVID-19 time and time again show excellent safety profiles, including the data for children," Day said.

Most recently, the Pfizer vaccine was authorized for kids ages 5-11 based on results from a clinical trial of 2,268 children that showed no new safety concerns. Previous research on the Pfizer vaccine in kids ages 12-15 showed side effects similar to those reported in adults, including pain at the injection site, fatigue and headache.

Day says these side effects generally are less severe in children than adults. "Your child may feel flu-like symptoms for a few days, but it's short-lived," Day said.

If your child is uncomfortable, you can treat post-vaccine symptoms with over-the-counter medications such as acetaminophen or ibuprofen. (However, experts say you should not give your child medication before they get the vaccine because it's unclear how they might affect the immune response.)

Is the vaccine effective in children?

Yes. In the two clinical trials that Pfizer has done in children, both show the vaccine to be very effective.

In the study of kids ages 5-11, a dose one-third the amount given to adults and teens showed 90.7% effective at preventing infection with symptoms, meaning most of the kids in the clinical trial did not get sick. In the earlier study of kids ages 12-15, there were no infections among the kids who got the vaccine.

If kids generally have less severe cases of COVID-19, why should they be vaccinated? 

The first reason is to avoid potentially severe illness and long-term symptoms from a COVID-19 infection.

Although kids generally have less severe cases of COVID-19 than adults, they do experience severe COVID-19 including hospitalization and death. In addition, there are rare but severe complications, such as multisystem inflammatory syndrome in children (MIS-C). This condition, in which different organ systems like the heart and lungs become inflamed, is most common among children younger than 10.

The second reason is to protect your whole family and your community, especially those who are too vulnerable to get the vaccine or for their vaccines to work as intended. The more people who are vaccinated, the slower COVID-19 will spread. This is called herd immunity.

"Kids and adolescents make up about 22% of our population, so they're an incredibly important part of achieving herd immunity," Day said.

When will younger children be eligible?

Multiple manufacturers are studying their vaccines in children as young as 6 months old, but there is no timeline yet for health officials to consider authorizing vaccines for even younger kids.

Vaccines are always tested first in adults to ensure their safety before moving down the age ranges to adolescents then younger children.

"This progression helps researchers ensure the vaccine's safety and determine the right dose for children," Day said.

How did researchers determine the dose of vaccine for young children?

The dose of vaccine authorized to use in children age 5 to 11 is smaller than the adult and adolescent dose — only about one-third of the amount. This is not due to children's smaller size as many people assume, but instead relates to the strongly reactive immune systems in young patients. The lower dose was thoroughly tested to be sure children create enough antibodies to protect them and minimize any side effects from the vaccine.

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