Pfizer says its COVID-19 vaccine is safe and works well for kids ages 5–11

A lower dose prompted as many antibodies in kids as a full-dose did in teens and young adults

a small girl sits with her mom in an exam room as a nurse administers Pfizer's COVID-19 vaccine

Nine-year-old Marisol Gerardo gets her second COVID-19 shot as part of a clinical trial to test how well Pfizer’s vaccine works in kids.

Shawn Rocco/Duke Health

Elementary school–age children may soon be able to get a COVID-19 vaccine.

Pharmaceutical giant Pfizer and its German biotech company partner BioNTech reported September 20 that a low dose of their mRNA vaccine is safe for children.

There are hints that the vaccine also protects against the coronavirus. The 10-microgram shots given to kids aged 5- to 11-years-old is a third of the dose given to people 12 and older. Yet after getting two shots 21 days apart, the younger kids produced levels of protective antibodies comparable to the levels made by 16- to 25-year-olds given two full doses. The companies, which shared the early results via a news release, did not report any data on protection against infection, hospitalization or death from the virus.

That preliminary report is promising, says Debbie-Ann Shirley, a pediatric infectious diseases doctor at the University of Virginia in Charlottesville and medical director of the COVID-19 clinic. Side effects from the vaccine were similar to those seen in older children with most being “brief, quickly resolved and mild.”

Pfizer indicated that it will soon seek emergency use authorization from the U.S. Food and Drug Administration for use of the vaccine in 5- to 11-year-olds. Both the FDA and Centers for Disease Control and Prevention must still vet and sign off on use of the vaccine in kids. “We’re still a couple of steps away before we might be able to put it into the arms of children,” Shirley says.

The news comes as cases of COVID-19 among children remain at their highest levels since the pandemic began, mostly driven by infections with delta variant. In the United States, nearly 226,000 children were diagnosed with the disease in the week ending September 16, according to the American Academy of Pediatrics. While COVID-19 remains a mild disease for most who become infected, a total of 516 children have died of COVID-19 since the beginning of the pandemic, including 100 who died since August 4 (SN: 8/9/21).

Along with the upsurge of cases, hospitalizations of children with COVID-19 have also skyrocketed, taxing pediatric health systems in some places. Most of the adolescents hospitalized are unvaccinated, even though they are eligible to get the shots, Shirley says. Nationally, about 52 percent of 12- to 17-year-olds have gotten at least one dose of a COVID-19 vaccine, CDC data show.

Also troubling is that doctors are now seeing an uptick in cases of MIS-C, an inflammatory condition that strikes weeks after a COVID-19 infection. Even if the initial infection was mild or asymptomatic, the inflammatory syndrome can cause organ failure and death in otherwise healthy children. At UVA, “last week we started to see an increase in MIS-C cases right on target,” Shirley says.

Tina Hesman Saey is the senior staff writer and reports on molecular biology. She has a Ph.D. in molecular genetics from Washington University in St. Louis and a master’s degree in science journalism from Boston University.