FDA Authorizes COVID-19 Vaccines for Children as Young as 6 Months

kids vaccine

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Key Takeaways

  • FDA authorized Pfizer and Moderna COVID-19 vaccines for children 6 months and older.
  • Experts say it's important to have the vaccine options available to young kids, especially those who are most vulnerable to COVID-19.

The Food and Drug Administration (FDA) on Friday authorized the Pfizer and Moderna COVID-19 vaccines for emergency use in children as young as 6 months, more than a year after authorizing the shots for adults.

The authorization was followed by support from the Centers for Disease Control and Prevention (CDC) on Saturday, meaning vaccination can begin in young children. So far, all states besides Florida have preordered vaccines for young children.

Earlier this week, an FDA advisory panel voted unanimously to recommend the Pfizer shot for children 6 months through 4 years, and the Moderna shot for those 6 months through 5 years.

Pfizer vs Moderna Authorization

For the youngest kids:

  • Pfizer’s regimen is administered as three shots, with three weeks between the first two shots, and at least eight weeks between the second and third.
  • The Moderna primary series includes two shots, given one month apart with a third dose available to some children with immunosuppression. 

Additionally, the FDA authorized Moderna's vaccine for children aged 6 through 17.

During the two-day meeting, panelists emphasized the clinical and social benefits of vaccinating children against COVID-19, both for their health and for society at large.

“I know that the death rate from COVID in young children may not be extremely high, but it’s absolutely terrifying to parents to have their child be sick and have to go to the hospital,” said Jay Portnoy, MD, a professor of pediatrics at Children’s Mercy Hospital in Kansas City, Mo.

Vaccinating the Youngest Children

The FDA panelists emphasized that children can get seriously ill and be hospitalized from COVID-19. Cases and hospitalizations among infants and young children increased alongside adults during the Omicron wave. Throughout the pandemic, roughly one in four children required ICU admission.

While some panelists emphasized that the risk of death from COVID-19 is relatively low, others applauded the ability to offer a vaccine option for children, especially those who are most vulnerable to severe illness from COVID-19.

Both vaccines appear substantially less effective at protecting against COVID-19 than the vaccines authorized for adults. But the companies and regulators said much of the difference was due to the ability of Omicron and its subvariants to evade immune defenses.

For each of the vaccines, panelists said it’s likely that an additional dose will be required to protect against future variants. This means Moderna recipients may need three shots to be fully protected and Pfizer vaccinees may eventually need four.

The manufacturers each tested several dose sizes to minimize the risk of fever and other side effects in kids. Pfizer landed on a dose that is just a tenth of the strength given to adults, and Moderna chose a dose a quarter the strength of its adult vaccine.

Pfizer’s Efficacy & Safety Data

Pfizer initially asked the FDA to authorize a two-dose series. But the company also presented data on a three-dose primary series and the panelists agreed that the vaccine regimen should include all three shots.

A two-dose primary series elicited an immune response in nearly all the children during trials, but it was only about 22% effective at protecting against infection during the Omicron wave.

Paul Offit, MD, a panelist and director of the Vaccine Education Center at Children’s Hospital of Philadelphia, called the data “surprising.”

“It does worry me actually that there was no protection after dose two,” he said.

Adding a third dose boosted efficacy to about 80%, according to additional data presented by Pfizer officials. But that data was based on about cases in only three vaccinated and seven placebo participants.

Besides, some panelists questioned the feasibility of asking parents to have their kids vaccinated three times. Allowing children to be vaccinated against COVID-19 at the same time as other routine childhood vaccinations could help, but Pfizer hasn’t collected data about how this would influence vaccine efficacy.

“For people who have gotten two doses of that vaccine, they have to know they’re not protected,” Offit said. “I wonder whether parents will understand that.”

Side Effects from the Pfizer Vaccine

Study participants generally had mild or moderate symptoms that were resolved within a few days. The most common reactions among toddlers were injection site pain, fatigue, and injection site redness, while the infants aged 6 to 23 months most commonly experienced irritability, drowsiness, decreased appetite, and tenderness at the injection site. Only six vaccine recipients experienced a high-grade fever and none were hospitalized. There were no cases of a severe reaction.

Amanda Cohn, MD, a top CDC official and panelist, questioned how long the interval should be between the second and third doses. Pfizer officials suggested it should be eight weeks, although the study participants had a median of 13 weeks between shots.

Doran Fink, MD, PhD, acting deputy director of the FDA’s vaccine division, said that Pfizer’s data is enough to conclude that the benefit of vaccinating this age group outweighed the risks. But he said he considered the data to be “imprecise and potentially unstable.”

“In terms of what the efficacy is after a third dose and whether an additional dose beyond that is needed will require more data,” Fink said.

Moderna’s Efficacy & Safety Data

Moderna’s vaccine for infants created antibody levels similar to those observed in teens and young adults, but lower than seen in older children. However, Moderna collected data for the youngest age group during the Omicron wave, while the older children were vaccinated before the variant was dominant.

The two-dose vaccine was 50.6% effective for infants 6-23 months old and 36.8% effective for kids 2 to 5 years old. The company said this is on par with the protectiveness of vaccines in adults infected with Omicron.

Jacqueline Miller, MD, senior vice president at Moderna called the data on Moderna’s vaccines “remarkably consistent across age groups,” despite the lower dosage for younger children.

Side Effects from the Moderna Vaccine

The side effects were mostly mild and moderate. About a quarter of the infants experienced fever—most were moderate and resolved after two days. One study participant experienced a fever and seizure related to the vaccine.

Though the young recipients of Moderna’s vaccine developed a fever at a higher rate than those in Pfizer’s study, they also appeared to be more protected against symptomatic Omicron infection after two doses.

Moderna is also currently testing boosters for this age group. Miller said the company is in the final stages of planning a study of its vaccine in children 3 months to 6 months old.

It’s Up to Parents to Make Vaccine Decisions

Some parents remain resistant to having their children vaccinated. In a Kaiser Family Foundation poll from April, one in five parents of children younger than 5 said they are eager to have their child vaccinated right away. About 4 in 10 said they would “definitely not” have their child vaccinated, or would only do so if required.

Despite the unanimous votes to authorize the vaccines for toddlers and infants, panelists were divided on how important vaccination for kids is.

Cody Meissner, MD, a professor of pediatrics at Tufts University, compared the chance of a young child dying from COVID-19 to that of getting struck by lightning. Other panelists urged their colleagues not to downplay the significance of COVID-19 as a pediatric disease with far-reaching consequences.

“There are so many parents who are absolutely desperate to get this vaccine,” Portnoy, a pediatrics professor, said. “I think we owe it to them to give them the choice.”

What This Means For You

Vaccines for young kids and adolescents may become available later this week. Experts caution that children are not fully vaccinated until two weeks after receiving two or three doses of the vaccine.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Delahoy MJ, Ujamaa D, Taylor CA, et al. Comparison of influenza and COVID-19-associated hospitalizations among children < 18 years old in the United States—FluSurv-NET (October-April 2017-2021) and COVID-NET (October 2020-September 2021). Published online May 20, 2022. Clin Infect Dis. doi:10.1093/cid/ciac388

  2. Food and Drug Administration. Vaccines and Related Biological Products Advisory Committee meeting June 15, 2022. FDA briefing document: EUA amendment request for Pfizer-BioNTech COVID-19 vaccine for use in children 6 months through 4 years of age.

  3. Food and Drug Administration. Vaccines and Related Biological Products Advisory Committee meeting June 14-15, 2022. FDA briefing document: EUA amendment request for use of the Moderna COVID-19 Vaccine in children 6 months through 17 years of age.

By Claire Bugos
Claire Bugos is a health and science reporter and writer and a 2020 National Association of Science Writers travel fellow.