Your Questions About the Coronavirus Vaccine in Children, Answered

Pfizer and BioNTech have asked the FDA to authorize use of their vaccine in kids ages 5 to 11. Kids 12 and up are already eligible.

covid vaccine Photo: Getty Images

On Thursday morning, Pfizer and BioNTech announced that they had officially requested that the Food and Drug Administration authorize use of their vaccine in children ages 5 to 11. A vaccine advisory panel for the FDA will meet Oct. 26 to discuss the request.

In early May, the FDA authorized the use of the Pfizer-BioNTech coronavirus vaccine in children ages 12 to 15. As of Oct. 6, 54.9 percent of 12- to 15-year-olds had received at least one vaccine dose, and 44.6 percent of this population was fully vaccinated, according to data from the Centers for Disease Control and Prevention.

“Having a vaccine authorized for a younger population is a critical step in continuing to lessen the immense public health burden caused by the COVID-19 pandemic,” said Peter Marks, MD, director of the FDA’s Center for Biologics Evaluation and Research. “The FDA can assure the public and medical community that the available data meet our rigorous standards to support the emergency use of [the Pfizer] vaccine in the adolescent population 12 years of age and older.”

More on COVID-19

Getting children vaccinated is essential for controlling the COVID-19 pandemic, says Gregory Poland, MD, director of the Vaccine Research Group at the Mayo Clinic, who studies vaccine response in adults and children. “If you want your child to go to school, if you want them to be safe, to have the normal social experiences that are important to childhood, please protect them by getting them vaccinated,” he says.

On Sept. 20, Pfizer and BioNTech announced that in children 5 to 11, a smaller dose of that vaccine than the one adults get generated infection-fighting antibodies in kids and appeared to be safe. Pfizer and BioNTech submitted data from this trial to the FDA, which is part of what the FDA advisory committee will consider later this month.

This timeline could result in an authorization for this age group of kids by early November, says Tina Tan, MD, a pediatric infectious disease specialist and professor of pediatrics at Northwestern University.

To better understand what we know about COVID-19 vaccines for children, CR consulted with experts and reviewed the available data. Here are answers to some common questions parents may have.

Do Kids Really Need to Get Vaccinated Against COVID-19?

Yes, they should.

In the early months of the pandemic, scientists learned that children and teens were less likely to get severely ill with COVID-19, though some still became very sick. So far, children make up about 13 percent of COVID-19 cases overall in the U.S., with adolescents more likely to develop severe disease like adults, says Kathryn Edwards, MD, scientific director of the Vanderbilt Vaccine Research Program and a professor of pediatrics.

But children are a significant share of new cases now.

Some of that is because as adults get vaccinated, they’re less likely to get infected, making children a greater proportion of overall cases. But another reason, Poland says, is that variants of the virus now circulating are more infectious. And that makes vaccinating children, who have always faced some risk from the virus, even more urgent.

The emergence of the highly contagious Delta variant of the coronavirus has led to a surge in cases for everyone, kids included, Tan says. “For the two weeks ending September 9, there were over 500,000 cases of COVID-19 in children,” she says. Even if Delta isn’t more dangerous for kids, the increase in contagiousness means a lot more kids are ending up in the hospital, says Sean O’Leary, MD, a professor of pediatrics at the University of Colorado School of Medicine and an infectious disease specialist at Children’s Hospital Colorado. That highlights the urgency of getting more people—kids and adults—vaccinated. The surges in pediatric hospitalizations are especially bad in places with lower vaccination rates for adults and adolescents, he says.

Many of these kids—including many who were never hospitalized—deal with lingering symptoms that can persist long after infection, Tan says.

Vaccination also helps prevent other serious outcomes in children, Edwards says. In rare cases, children who have had COVID-19 have developed a condition known as MIS-C, which can cause organ damage and even death. Scientists are also following children who have gotten COVID-19 to see whether any have lingering problems, especially cardiac issues. 

Are the Vaccines Effective in Kids?

So far, efficacy data on the Pfizer-BioNTech vaccine in children looks “stellar,” says Poland at the Mayo Clinic. (Poland has consulted with Pfizer, Moderna, and Johnson & Johnson on the development of their vaccines.)

According to Pfizer and BioNTech, a clinical trial of that vaccine in 2,260 12- to 15-year-olds found it 100 percent effective at preventing COVID-19. Children in that age group had even higher levels of antibodies in response to the vaccine than 16- to 25-year-olds.

In Pfizer and BioNTech’s Sept. 20 announcement, the companies said there were 2,268 kids ages 5 to 11 in their more recent trial. These kids also generated antibodies at least as strong as those in people ages 16 to 25, with a smaller dose of the vaccine, according to the announcement. The companies hope to have data on vaccine effectiveness in kids ages 6 months through 4 years before the end of the year.

In May, Moderna announced that its clinical trial of 3,732 people ages 12 to 17 showed that adolescent immune systems responded to its vaccine at least as well as the immune systems of adults. The company also reported that its vaccine, which uses similar technology to the Pfizer-BioNTech vaccine’s, was not only 100 percent effective two weeks after the second dose but also 93 percent effective two weeks after the first dose. 

On June 10, Moderna requested FDA authorization for use of its vaccine in people ages 12 to 17, after reporting that clinical trials showed it was effective in adolescents. The FDA has not yet granted that authorization and has not provided further updates. Canada’s public health agency has said it found a relatively higher risk of myocarditis with the Moderna vaccine compared with Pfizer, and in October, Denmark and Sweden paused the use of the Moderna vaccine in younger age groups because of potential cardiovascular side effects.

It’s likely that in the real world these vaccines may be somewhat less than 100 percent effective but still very protective, Poland says. Information on the effectiveness of vaccines made by Johnson & Johnson and Novavax in children may be available soon, too, he says. 

Do Kids Get the Same Shot As Adults?

Older kids do, though younger kids are likely to get smaller doses. In Pfizer-BioNTech’s clinical trial, 12- to 15-year-olds received the same vaccine and dosages as adults, on the same schedule, with a second dose three weeks after the first. In Moderna’s trial, 12- to 17-year-olds also received the same doses as adults. The FDA’s authorization for the Pfizer-BioNTech vaccine allows 12- to 15-year-olds to get the same dose as adults.

In children ages 5 to 11, Pfizer and BioNTech said a 10-microgram dose (one-third of the dose given to older children and adults) appeared to provide as much protection as the larger dose gives adults. And in children ages 6 months to 4 years, the companies are testing a 3-mcg dose.

Are the Vaccines Safe for Kids?

Common side effects reported in children so far are similar to those in adults: injection site pain, fatigue, headaches, muscle aches, chills, joint pain, and fever. And as in other age groups, these were “well tolerated” in 12- to 15-year-olds, Pfizer and BioNTech say.

The same sorts of symptoms were seen in 12- to 17-year-olds who received the Moderna vaccine, according to the company, with headaches, fatigue, achiness, and chills reported.

“The reaction profiles were pretty comparable to what we see in adults,” says Kathryn Edwards at Vanderbilt.

In mid-May, the CDC announced that it was investigating rare reports of heart inflammation—myocarditis and pericarditis—that have occurred after coronavirus vaccination, and the agency released additional data in June.

These cases have occurred mostly in male patients and have been more common after the second dose than the first. Importantly, there have been more reports of suspected myocarditis in people ages 16 to 24 after vaccination than would be expected normally for that population, according to CDC data.

But while it’s important that the CDC is transparent about these investigations, parents should understand that these events are still extremely rare, says David Parra, MD, a pediatric cardiologist and associate professor of pediatrics at Vanderbilt University. According to a June CDC study, there would be approximately 39 to 47 myocarditis cases in males ages 12 to 29 for every million second doses of the vaccine.

A risk-benefit analysis by the CDC suggests that for every million second doses of vaccine given to males ages 12 to 17, there could be 56 to 69 cases of myocarditis—but that these vaccinations would prevent 5,700 cases of COVID-19, 215 hospitalizations, 71 intensive care unit admissions, and two deaths. Still, in some countries, including the U.K. and Norway, health officials have recommended only a single dose for adolescents for now, to lessen the risk of side effects.

We also know that COVID-19 itself can cause inflammation in the heart and other organs, Parra says. “Vaccination is really important, and from what we know, the risks of COVID are much higher than the risks of vaccination,” he says. According to a September CDC report, kids younger than 16 who get COVID-19 are 37 times more likely to develop myocarditis than kids without COVID-19. That’s a significantly higher risk than the myocarditis risk associated with vaccination.

Poland says that experts will be watching closely to ensure that side effects aren’t a bigger problem for younger children. He adds that one reason to test lower dosages is to try to minimize side effects for the youngest children.

When Will Younger Children Be Eligible?

Children ages 5 to 11 could be eligible very soon. FDA advisors will be discussing Pfizer and BioNTech’s request for authorization Oct. 26, which means a vaccine could be authorized for these kids by early November. Data on younger kids is expected before the end of the year.

Still, the FDA and CDC need to review the data before recommending vaccinations for younger kids. “You want to show the vaccine is safe and effective in this population,” Tan says.

Edwards says exactly when younger children will be eligible depends on how the trials go. “We’re all working really hard to make sure the vaccines are safe and effective,” she says. “We will not go too fast. We will go in a careful, cautious manner.” 

Will Schools Require Kids to Be Vaccinated Against COVID-19?

More than 1,000 colleges and universities in the U.S. have required students to be vaccinated against COVID-19, according to a count by The Chronicle of Higher Education. Some high schools have as well. All students 12 and older in Los Angeles public schools, for example, must be vaccinated by Jan. 10, 2022.

Schools that serve younger children already often require proof of various immunizations before children enroll, but it’s not yet clear whether a COVID-19 vaccine will become one of them.

Right now, COVID-19 vaccines have an emergency use authorization from the FDA for kids under 16. Until vaccines receive full approval for younger age groups, Poland says he thinks most schools probably won’t require kids to have one. But after the FDA fully approves the vaccines for children, many schools are likely to require proof of vaccination, he says.

Edwards says she hopes that people are persuaded to get children vaccinated based on the “incredible success” we’ve seen the vaccines have at preventing disease so far. 

Editor’s Note: This article has been updated to include new data and information from the CDC, the FDA, Pfizer-BioNTech, and Moderna, as well as additional reporting. It was originally published May 4, 2021. 


Head shot image of CRO Health editor Kevin Loria

Kevin Loria

I'm a science journalist who writes about health for Consumer Reports. I'm interested in finding the ways that people can transform their health for the better and in calling out the systems, companies, and policies that expose patients to unnecessary harm. As a dad, I spend most of my free time trying to keep up with a toddler, but I also enjoy exploring the outdoors whenever possible. Follow me on Twitter (@kevloria).