FDA Postpones Decision on Pfizer COVID Vaccine for Kids Under 5

The U.S. Food and Drug Administration announced Friday that it will postpone an advisory panel meeting that was slated for next week to weigh Pfizer's COVID vaccine for use in young children.

The FDA took the step after Pfizer notified the agency that it would like to wait until data is available on a three-dose regimen for children aged 6 months to 4 years old, Pfizer said in a statement.

The FDA had planned to review a two-dose regimen at a Feb. 15 meeting of its Vaccines and Related Biological Products Advisory Committee meeting. This committee provides crucial review of the data behind vaccine applications.

The application now "will wait for the three-dose data as Pfizer and BioNTech continue to believe it may provide a higher level of protection in this age group," Pfizer said.

"This is also supported by recent observations of three-dose booster data in several other age groups that seems to meaningfully augment neutralizing antibody levels and real-world vaccine protection for Omicron compared to the two-dose regimen," the company added.

During a media briefing on the postponement, FDA officials explained their change in strategy.

"Given the recent Omicron surge and the notable increase in hospitalizations in the youngest children to their highest levels during the pandemic so far, we felt it was our responsibility as a public health agency to act with urgency and consider all available options, including requesting that the company Pfizer provide us with initial data on two doses from its ongoing study," said Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research.

"The goal was to understand if two doses would provide sufficient protection to move forward with authorizing the use of the vaccine in this age group. The [new] data that we saw made us realize that we needed to see data from a third dose in the ongoing trial in order to make a determination that we could proceed with doing an authorization," he said.

Marks also noted that the speed with which Omicron spread also speeded up the collection of trial data.

"Think about what's happened in the past month. I don't know whether anyone could have really predicted what happened real well. We had days when we were getting above three quarters of a million cases a day of Omicron, and we started to see a tremendous number of children affected by Omicron," Marks said. "You could imagine that if a clinical trial were going on, any clinical trial, not necessarily this one, where someone was looking at outcomes, one might see information coming in very quickly."

Pfizer first announced in December that a two-dose regimen didn't generate a strong enough immune response in some children.

"The decision to evaluate a third dose … for children 6 months to under 5 years of age reflects the companies' commitment to carefully select the right dose to maximize the risk-benefit profile," Pfizer said at the time.

The FDA had planned to go forward with a review of the two-dose series out of a sense of urgency, but the postponement should also reassure parents, Marks added.

"We take our responsibility for reviewing these vaccines very seriously because we're parents as well. In looking over these data, I think parents can feel reassured that we have set a standard by which we feel that if something does not meet that standard, we can’t proceed forward," Marks said.

"Rather than having any issue of causing anyone to question the process, I hope this reassures people that the process has a standard, that the process is one that we follow, and we follow the science in making sure that anything we authorize has the safety and efficacy that people have come to expect from our regulatory review of medical products," he said.