It has been roughly five months since the Pfizer COVID-19 vaccine was approved for children ages 5 to 11, and for kids in that age group, two shots are all that is recommended right now.
But in January, the Centers for Disease Control and Prevention said older kids (age 12 and up) should get a booster dose of the Pfizer vaccine if it has been five months since their second shot.
So could boosters be coming for younger kids, too? Especially those who were vaccinated early on?
Here’s what we know so far:
Yes, some experts believe boosters are likely.
“It is very likely that kids 5-11 will need a booster,” said Dr. Paul Spearman, director of the Division of Infectious Diseases at Cincinnati Children’s Hospital Medical Center (which is conducting multiple clinical trials of COVID-19 vaccines).
Spearman pointed to new data showing the Pfizer vaccine was not nearly as effective in preventing infection among vaccinated 5- to-11-year-olds during the recent omicron surge (although it did continue to protect against severe illness) — data that certainly raises questions about whether a booster would increase protection.
“Pfizer is studying booster doses in this age group, so we have to stay tuned to know how well the additional dose boosts vaccine responses,” Spearman said. “The answer may also depend upon what variants arise, but in general it is likely that a booster will be recommended at some point for this age group.”
Dr. Dane Snyder, section chief of primary care pediatrics at Nationwide Children’s Hospital, hedged a bit more, saying it’s probably too soon to know whether younger children will require COVID-19 boosters — or when.
Fewer young children are being followed in the research right now compared to adults and adolescents, and they weren’t eligible for the vaccine until last fall. All of that makes it more challenging to draw broad conclusions, Snyder said.
Still, he too said the recent data on COVID-19 vaccines among young kids with regard to the omicron variant raises real questions about whether a booster would help.
“While the primary vaccines have been effective in this group, the effectiveness may be lower than what we have seen in older children and adolescents who received a larger dose,” Snyder said. “That may indicate that a booster will be beneficial, but more information is still needed to make a recommendation one way or another.”
Some 5- to 11-year-olds already qualify for a third dose.
The CDC already recommends that children who are moderately or severely immunocompromised get a third COVID-19 vaccine dose 28 days after their second shot. That includes (but isn’t limited to) children with cancer or those who have had organ transplants.
It is important to keep in mind that an additional dose and a booster are not the same thing from a clinical perspective. A booster is given to an otherwise healthy person who has completed their vaccine series, but who is believed to have had the expected immune response after their initial shots.
For children with weakened immune systems, the additional dose is considered part of their primary COVID-19 vaccine series. All three doses they receive are smaller than those given to adolescents and adults.
What works for older kids doesn’t necessarily translate to younger kids.
There’s a reason the COVID-19 vaccine clinical trials in children have rolled out by age: Physiologically speaking, kids aren’t simply smaller adults, and younger kids aren’t just miniature adolescents. A 5-year-old is different from a 15-year-old not just because the teenager likely weighs more and is significantly taller; they have different heart rates and breathing rates. Their hormones behave differently. Their immune systems function in distinct ways.
That is why younger children receive a smaller dose than older children and adults. And it explains why public health officials and health care providers won’t start recommending boosters for 5- to 11-year-olds simply because they’re now recommended for adolescents and teens.
“We know that boosters in older adolescents do what we hoped they would do ― the booster does improve vaccine effectiveness,” said Snyder. “And we know that two vaccines does reduce the risk of infection and severe illness in the 5- to 11-year group, even in the midst of the omicron variant. But each age group needs its own research and information about boosters.”
Right now, getting more kids their first two shots is the priority.
While clinical trials are underway to determine whether boosters will eventually be recommended for 5- to 11-year-olds, pediatric health experts’ primary focus is getting more children their initial two shots. Uptake has been slower than health officials hoped for. Some 33% of 5- to 11-year-olds in the United States have received one dose of the vaccine at this point; 27% have received both.
Parents and caregivers should speak with their child’s pediatrician or another trusted health expert if they have any concerns. But they should also understand that millions of children have now safely rolled up their sleeves.
“I think parents should first be aware that these vaccines are extremely safe, and even those rare vaccine-related events like myocarditis are much less common in younger children,” Spearman said. “They are also quite effective, and although omicron lowered overall efficacy rates, we have to remember that the most important measure of protection is against severe disease, hospitalization and death. Current vaccines do very well in this important measure.”
Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.