OAKLAND, Calif. - Pfizer announced Monday that data from its clinical study of children ages 5 to 11 showed the COVID-19 vaccine produced an antibody response that matched levels seen in older children and adults.
Pfizer says it plans to submit data and apply for FDA emergency use authorization by the end of the month, followed shortly afterward with applications to European and British regulators. An independent committee, the FDA, and CDC will review the science before making a decision.
The study included children ages 5 to 11. They received two shots and each dose was just one third of the adult dosage.
"We measure the ability of antibody from the children that were vaccinated to kill the virus and how well that matched up the antibody from 16 to 25 year olds, and it matched very closely. And since we know that 16 to 25 year olds are protected and antibody is a good measure of that protection, having matched that antibody response, we're likely to match the protection," said Dr. Bill Gruber, a Pfizer senior vice president, "
The kid dosage also proved safe, with similar or fewer temporary side effects -- such as sore arms, fever, or achiness -- that teens experience, he said.
"I think we really hit the sweet spot," said Gruber, who's also a pediatrician.
The vaccine made by Pfizer and its German partner BioNTech already is available for anyone 12 and older. But with kids now back in school and the extra-contagious delta variant causing a huge jump in pediatric infections, many parents are anxiously awaiting vaccinations for their younger children.
At La Clinica de la Raza in Oakland's Fruitvale neighborhood, they are already making plans for distribution if the vaccine is approved for younger children.
"We are starting to make plans," said Dr. Lynne Rosen, a pediatrician and vaccination lead at La Clinica, "That includes having a mass vaccination clinic in the Fruitvale where we can accommodate large numbers of people."
Pharmacies are also expected to play a key role in administering to children as well pediatricians, and school sites.
"We also have been doing pop-ups at school sites. We plan to continue doing that for the other age group," said Rosen.
"I didn't really get any side effects. At least I feel protected so that's fine," said Karla Castillejos, an Oakland 11th-grader who says she got two vaccination doses.
Her sister Sophia Castillejos, 11, is an Oakland 6th grader who is waiting to see if the FDA approves a shot for her age group.
"I feel kind of prepared because I know my whole family got it. I'm not scared or anything," said Sophia, "I know it's all to protect someone so this whole pandemic can stop and we can get back to normal."
Even parents of children under 5 say they think vaccinating children ages 5-11 could benefit younger kids at daycare.
Katie Borrud, an Oakland mom, says she is worried about her son Carter, 2, picking up COVID-19 because he is not yet eligible for a vaccine and attends daycare.
"That's where he picks up a lot of the viruses, these larger daycares where a lot of older kids mix or they meet up with older kids later on in the day," said Borrud.
Health officials say children ages 5 to 11 have different immune systems than older children, thus the different dose.
"Five to 11 is quite different than 12 to 16 or 18, a very different group in terms of developmentally, including the development of their immune system and how it responds," says Dr. John Swartzberg, an expert in infectious diseases and a clinical professor emeritus from UC Berkeley's School of Public Health, " Pfizer is using a much lower dose for the children five to 11 that was used for 12 to 18, which is not surprising because they should get more bang for the buck in smaller children who tend to respond really well to vaccines."
Dr. Swartzberg says the timing of the vaccine rollout for children could be key to preventing another deadly surge such as the spike in cases last year after the winter holidays.
"On top of kids being back in school. We've got Halloween coming up in...people are going to be spending more time indoors as the winter progresses. And then on top of that you're going to have Thanksgiving, and you're going to have Christmas, and you're going to have New Year's, and we saw what happened last year with those holidays on top of people being indoors. It was a disaster," said Dr. Swartzberg.
Earlier this month, FDA chief Dr. Peter Marks told the 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 have. 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 the AP.
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.
Moderna is also 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.
The Associated Press contributed to this report.