In long-awaited data, Pfizer said its 3-dose vaccine was 80% effective against symptomatic omicron COVID-19 infection among children 6 months to under 5 years old.
The company cautioned that estimate was preliminary and could be adjusted as more data is collected. The trial wasn't big enough to estimate protection against severe disease, which experts expect to be higher.
For all age groups, vaccine efficacy against more mild breakthrough infections waned in the face of the highly transmissible omicron variant, but efficacy against severe disease and death remained high for most age groups.
Pfizer announced in December that it would not move forward with a two-dose vaccine after disappointing data, instead opting to study three doses for this age group. The company will submit the new data as part of its ongoing “rolling” submission to the FDA.
For anxious parents, the Pfizer news offers reassurance that the vaccine help protect young children currently not eligible for vaccination.
The news doesn’t change the overall timeline for when vaccines for this age group could be available. For the youngest Americans, vaccines from both Pfizer and Moderna are expected to be authorized in June or July, likely as a two-dose vaccine for Pfizer and a three-dose vaccine for Moderna, though Moderna is also studying a third dose.
Pfizer also said its vaccine was safe, with a similar safely profile as placebo shots. If authorized, this vaccine would be 3 shots of 3 micrograms each. Each dose is one-tenth the adult dose.
“We are pleased that our formulation for the youngest children, which we carefully selected to be one-tenth of the dose strength for adults, was well tolerated and produced a strong immune response,” said Albert Bourla, Pfizer's chairman and chief executive officer, in prepared remarks.
Moderna, meanwhile, asked the FDA for authorization on April 28 for a two-dose vaccine for this age range. Moderna’s preliminary analysis found its two-dose pediatric vaccine was 51% effective against symptomatic COVID-19 among children 6 months to under 2 years old, and 27% among children 2 to 5 years old -- roughly the same efficacy seen in adults during the omicron surge. Protection against serious disease and death was higher.
"I anticipate a lot of parents will be asking whether they should choose a two-dose Moderna vaccine or the three-dose Pfizer vaccine," said Dr. Alok Patel, pediatric hospitalist at Stanford Children's health and an ABC News contributor. "I would recommend that parents pay attention to the FDA and CDC’s guidance and what final analysis reveals for both vaccines."
Experts caution that vaccine efficacy against symptomatic infection is a high bar, and experts expect these vaccines will offer excellent protection against severe illness, just as they do for adults.
This development means Pfizer is one step closer to submitting its vaccine for an emergency use authorization. It will likely be reviewed by the FDA’s advisers at meetings on June 21 and 22, and if authorized, be available sometime in early July.
It’s possible that the FDA’s advisers could review Moderna’s data even earlier -- on June 8 -- but no agenda has been released. It also depends on the time it takes FDA to sift through Moderna’s application, which includes a request to authorize its vaccine not only for the youngest kids, but also kids 6 to 17.
Though the FDA’s leaders have repeatedly said they would not unnecessarily hold up Moderna’s authorization, it’s possible that the FDA’s panel of independent experts call for authorizing Moderna and Pfizer side-by-side.
Because they’re both for the same general age group but are different vaccines with different levels of protection, some experts believe it will be easier to authorize them together and allow parents to choose which vaccine to give their kids with all of the information available.
But many parents and pediatricians want the vaccine that’s available soonest, after two grueling years of waiting.
Though children under five is the last remaining age group that’s yet to be vaccinated, polls indicate there could be sluggish uptake.
A recent survey from KFF found that just under 1 in 5 parents are eager to get their children under five vaccinated right away.
However, the KFF poll more than half of parents said that they feel they do not have enough information about the vaccines’ safety and efficacy for children under age 5 — which could change after the public FDA advisory meetings to discuss the pediatric data.
"Parents should also be aware that this preliminary data will be supplemented by additional data in June, which will then be thoroughly reviewed by both the FDA and the CDC," Patel said.
