Here’s What You Need To Know About Pfizer’s COVID Vaccine For Kids Under 12

Theresa Tamkins
·7 min read

The US moved closer toward COVID-19 vaccines for children under 12 after the FDA authorized the Pfizer vaccine for them on Friday.

"Vaccinating younger children against COVID-19 will bring us closer to returning to a sense of normalcy,” said acting FDA Commissioner Janet Woodcock, in a statement.

Following a contentious daylong discussion on Tuesday, a panel of outside advisers to the Food and Drug Administration voted 17–0 (with one abstention) to recommend authorizing the two-dose vaccine for kids ages 5 to 11. The group decided that the vaccine’s benefits outweigh the risks and that it is safe and effective for preventing infections.

The approval was based on a study that looked at two 10-microgram doses of the vaccine, one-third the dose given to adults, given three weeks apart. It was more than 90% effective at preventing symptomatic COVID-19 in the study of 2,268 children.

The FDA authorization and the panel's recommendation doesn’t mean you can get your kids under 12 vaccinated just yet. (Children 12 and older are already eligible to get a Pfizer vaccine, and the CDC recommends that they do so.)

Still to come, an advisory panel for the Centers for Disease Control and Prevention will also give its recommendation to states next week. If the CDC agrees, shots could be available for kids under 12 as soon as November. Some cities are already scheduling shots as early as the second week of the month.

In anticipation of the decision, the Biden administration announced last week that it had already procured enough of the Pfizer vaccine to vaccinate the country’s 28 million children in this age range. Officials plan to make vaccines available for free at doctor’s offices, children’s hospitals, pharmacies, and school- and community-based clinics.

However, some FDA advisory panel members voiced concerns over the lack of data on whether one dose, rather than two, might be sufficient; whether it was appropriate to recommend approving the vaccine only for high-risk children; or if the decision would be used to justify vaccine mandates.

While some governors have indicated that they will mandate vaccinations for kids 5 and up who attend school, such moves are sure to be contentious.

The vote comes as cases and hospitalizations have been steadily declining in the US. But kids are now making up a bigger share of cases and hospitalizations, coinciding with the surge of the highly contagious Delta variant and the beginning of the school year.

On Monday, Moderna announced its two-shot vaccine appeared to generate an immune response similar to young adults in children ages 6 to 11, with similar side effect rates. Moderna said it would soon submit its data to FDA for authorization.

How are kids’ vaccines different from shots for adults?

The Pfizer vaccine for kids is not only a lower dose of the version that adults and adolescents get — 10 micrograms vs. 30 micrograms — it’s a different formulation that is easier to store at low temperatures.

The kids’ version can be stored for up to 10 weeks in a refrigerator, compared with the adult version, which can only be stored in a regular freezer for up to two weeks prior to use. Both versions are stored in an ultracold freezer (minus 80 degrees Celsius) until they are distributed or reach the expiration date.

The vaccines for young children will also have orange caps, to differentiate them from the purple-capped vaccines for people 12 or older. This will help ensure that every kid who gets Pfizer’s COVID-19 vaccine gets the intended dose.

How dangerous is COVID-19 for kids?

Children are thought to be just as likely as adults to be infected with the SARS-CoV-2 virus, but less likely to become very sick or need to be hospitalized. However, due to rising cases, the infection was the eighth leading cause of death in children ages 5 to 11 in the last 12 months, according to CDC data.

As of Oct. 16, there have been 94 COVID-related deaths in children aged 5 to 11, making up about 1.7% of all deaths in that age group.

“Far from being spared from this harm of COVID-19, in the 5- to 11-year-old age range there have been over 1.9 million infections, over 8,300 hospitalizations (about a third of which required intensive care unit stays), and over 2,500 cases of multisystem inflammatory syndrome (MIS-C) from COVID-19,” said Dr. Peter Marks, director of the Center for Biologics Evaluation and Research at the FDA.

MIS-C is a rare and serious COVID-19 complication that causes fever, rash, swelling, and heart complications in children. More than 5,000 kids and teens have developed MIS-C, and half of those are aged 5 to 13.

Although children with diabetes, asthma, obesity, or other health issues are at higher risk from COVID, about one-third of children hospitalized for COVID don’t have an underlying health condition. Compared with white or Asian children ages 5 to 11, COVID hospitalization rates are more than three times higher for children who are Black, Latinx, or Native American.

With the rise of the highly contagious Delta variant, children are making up a greater proportion of people who get sick. Kids ages 5 to 11 made up nearly 11% of cases reported to the CDC the week of Oct. 10 although they make up only 8.7% of the population.

COVID-19 is often compared to the flu. Fiona Havers, medical officer for the Division of Viral Diseases at the National Center for Immunization and Respiratory Diseases, said school closures and mask-wearing drove flu rates down last season — only 9 children were hospitalized for flu in the 2020-2021 season — while COVID hospitalizations were similar to those for the flu in previous years. (More than 39,000 children were hospitalized in the 2018-2019 flu season.)

“This suggests that the annual rate of COVID-19 hospitalizations would have been much higher than those for influenza during typical influenza season had these mitigation measures not been in place,” Havers said.

Observed rates of long-lasting symptoms, or “Long COVID,” are much higher in adults than kids. Fewer than 1 in 20 children diagnosed with COVID-19 have symptoms lasting longer than four weeks, according to a study from the UK, and only 1 in 50 still have symptoms after eight weeks.

What are the risks and benefits of the COVID vaccines for kids?

The side effects of the Pfizer vaccine in the kids studied were usually mild and occurred in the first day or two after the injection. The most common side effects were pain at the injection site, fatigue, headache, and muscle pain.

The study reported no cases of myocarditis, a type of heart muscle inflammation, in three months. Myocarditis is a rare side effect mostly seen in teens or young men in their 20s given the Pfizer vaccine. It occurs in about 2 in 100,000 cases after a shot, according to a recent study from Israel. Myocarditis can also be caused by COVID itself and is 16 times more common in people with COVID than people who have not been infected. Heart inflammation caused by the virus is typically more severe than vaccination-associated cases, which usually respond well to medicine and rest, according to the CDC.

At the FDA advisory panel meeting, the health experts weighed this risk against the possibility of a continuing increase in cases. If there is a winter surge or case numbers remain at current levels, the number of COVID-19 cases, hospitalizations, and deaths in kids that would be prevented by vaccination clearly exceeded the risk of myocarditis, the analysis found. Vaccinating kids would also help prevent cases in older adults and those at higher risk of getting infected.

In the end, the vote came down to assuring that vulnerable children get the option of being vaccinated, said panel member and Chief Medical Officer for the CDC’s Vaccine Task Force Amanda Cohn, given current high rates of COVID nationwide and no assurance that another surge in cases won’t come this winter.

“We do not want children dying of COVID,” she said. “At this moment, the benefits do outweigh the risks.”

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