Pfizer Used Smaller Dose of COVID Vaccine to Test Children Under 12, Says It's Safe

Pharmaceutical company Pfizer said that it used a smaller dose of its COVID-19 vaccine to conduct tests with children under 12 and found the treatment to be safe, the Associated Press reported.

Pfizer announced Monday that it would be seeking approval in the U.S. to begin administering the shot to children between 5 and 11 as nationwide concern grows regarding rising cases of the virus in the unvaccinated age group.

The vaccine was previously granted full approval from the U.S. Food and Drug Administration (FDA) for anyone 12 and older, leaving those under the eligibility threshold particularly vulnerable as schools resumed classes and pediatric cases jumped.

Pfizer Senior Vice President Dr. Bill Gruber said that when conducting tests for kids between 5 and 11, Pfizer administered one-third of the dose given to older groups, yet found that younger children developed the same levels of antibodies as teens and young adults who got the full dose.

The tests also found the vaccine to be safe for younger children, who experienced similar or less of the temporary vaccine side effects that were seen in teens, Gruber said.

"I think we really hit the sweet spot," he said.

For more reporting from the Associated Press, see below.

Pfizer Vaccine Injection
Pfizer said that it tested its COVID-19 in children ages 5 to 11 with one-third of the dosage amount given to older populations and found that it was safe and effective for the age group. David Goldman/AP Photo

Gruber said the companies aim to apply to the FDA by the end of the month for emergency use in this age group, followed shortly afterward with applications to European and British regulators.

Earlier this month, FDA chief Dr. Peter Marks told AP that once Pfizer turns over its study results, his agency would evaluate the data "hopefully in a matter of weeks" to decide if the shots are safe and effective enough for younger kids.

An outside expert said scientists want to see more details but called the report encouraging.

"These topline results are very good news," said Dr. Jesse Goodman of Georgetown University, a former FDA vaccine chief. The level of immune response Pfizer reported "appears likely to be protective."

Many Western countries so far have vaccinated no younger than age 12, awaiting evidence of what's the right dose and that it works safely. Cuba last week began immunizing children as young as 2 with its homegrown vaccines and Chinese regulators have cleared two of its brands down to age 3.

While kids are at lower risk of severe illness or death than older people, more than 5 million children in the U.S. have tested positive for COVID-19 since the pandemic began and at least 460 have died, according to the American Academy of Pediatrics. Cases in children have risen as the delta variant swept through the country.

"I feel a great sense of urgency" in making the vaccine available to children under 12, Gruber said. "There's pent-up demand for parents to be able to have their children returned to a normal life."

In New Jersey, 10-year-old Maya Huber asked why she couldn't get vaccinated like her parents and both teen brothers. Her mother, Dr. Nisha Gandhi, a critical care physician at Englewood Hospital, enrolled Maya in the Pfizer study at Rutgers University. But the family hasn't eased up on their masking and other virus precautions until they learn if Maya received the real vaccine or a dummy shot.

Once she knows she's protected, Maya's first goal: "a huge sleepover with all my friends."

Maya said it was exciting to be part of the study even though she was "super scared" about getting jabbed. But "after you get it, at least you feel like happy that you did it and relieved that it didn't hurt," she told AP.

Pfizer said it studied the lower dose in 2,268 kindergartners and elementary school-aged kids. The FDA required what is called an immune "bridging" study: evidence that the younger children developed antibody levels already proven to be protective in teens and adults. That's what Pfizer reported Monday in a press release, not a scientific publication. The study still is ongoing, and there haven't yet been enough COVID-19 cases to compare rates between the vaccinated and those given a placebo—something that might offer additional evidence.

The study isn't large enough to detect any extremely rare side effects, such as the heart inflammation that sometimes occurs after the second dose, mostly in young men. The FDA's Marks said the pediatric studies should be large enough to rule out any higher risk to young children. Pfizer's Gruber said once the vaccine is authorized for younger children, they'll be carefully monitored for rare risks just like everyone else.

A second U.S. vaccine maker, Moderna, also is studying its shots in elementary school-aged children. Pfizer and Moderna are studying even younger tots as well, down to 6-month-olds. Results are expected later in the year.