This story has been updated to reflect the FDA’s June 17 authorization of Moderna’s and Pfizer’s vaccines for kids as young as six months.
On Friday June 17, the US Food and Drug Administration (FDA) granted emergency use authorization (EUA) for a covid-19 vaccine for children under five years old. The authorization comes days after the FDA panel endorsed the vaccines made by Moderna and Pfizer-BioNTech, reviewing clinical trial data and determining that they are safe and effective. Though the EUA is not full approval from the regulatory body, it’s a key step in making immune protection possible for some 23 million US children—a relief for parents worried about kids getting sick or bringing infection home.
Kids five and up are already authorized to get vaccinated (and boosted) per prior FDA authorizations, so it’s children between six months and five years who are affected. Both Moderna’s and Pfizer’s vaccines have now been granted authorization for use in children as young as six months, as well as in adults.
Though evidence suggests that children are just as likely as adults to get sick with covid-19, their symptoms tend to be more mild. However, that’s not universally the case—at least 442 children under four have died from covid as of May 28, according to the US Centers for Disease Control and Prevention (CDC). Studies suggest that 2% to 10% of children who get covid can have long covid symptoms. Kids can also get a rare condition called multisystem inflammatory syndrome in children (MIS-C), which causes inflammation in a number of organs and can be life-threatening.
Since children can get sick just as frequently (even if they aren’t showing severe symptoms), they risk passing the virus to others who might risk getting more sick.
To this end, children are key to reaching herd immunity. “It’s unlikely we could get community protection without immunizing children,” Sarah Long, a pediatrics professor at Drexel University told the AP last year. “This is the lynchpin to getting everything back to some kind of normalcy.”
In clinical trials, Moderna’s two-shot course was 51% effective in kids under two, and 37% effective in kids between two and six at preventing the infection with the omicron strain of SARS-CoV-2 (it noted it was studying the effects of a booster as well). Pfizer’s three doses offered 80% efficacy for kids between six months and five years.
The side effects in kids were generally milder than those for adults. For Pfizer’s shot, the most common side effects in kids 6 to 23 months were irritability (68%), drowsiness (41%), and decreased appetite (39%); in kids two to four years old they were pain at the injection site (47%), fatigue (45%), and injection site redness (19%). For Moderna’s in kids 6 to 36 months, they were irritability (82%), pain at the injection site (56%), and drowsiness (51%).
One key difference is the size of the dose—Pfizer’s kid’s shot is one tenth that for adults, and Moderna’s is a quarter. Another is the timing: while Pfizer’s first two shots are three weeks apart, as are its adult shots, its third dose is at least two months after the second (the CDC recommends adults get a booster after five months). Moderna’s two doses are given four weeks apart, as are its adult shots.
As New Scientist points out, seven other countries have vaccines approved for kids three and up. Why has it taken the US so long? It may be in part because the FDA reportedly chose to wait until it could evaluate both Moderna’s and Pfizer’s vaccines together to be “simpler and less confusing” for parents, according to Politico.
Giving vaccines to healthy kids also, understandably, requires regulators to be certain that the vaccines are safe and effective. After Moderna submitted its paperwork to regulators, studies raised the possibility of elevated risk of myocarditis, inflammation of the heart, in 18- to 24-year-olds. Regulators ultimately found this risk to be the same as with Pfizer’s vaccine, but Time suggests this may have delayed the process as well.
Shots could start going into arms as early as next week. Before that happens, though, the CDC will convene its own panel to determine how to recommend who uses the vaccines, per PBS. After that, vaccine distributors can start rolling out vaccines to distribution centers and pediatrician offices. Though some have questioned how much parents of young kids will want these vaccines, from a public health perspective, they’re a key step towards putting the pandemic behind us.