Pfizer and BioNTech on Friday said they are delaying completing their request for the Food and Drug Administration (FDA) to authorize their coronavirus vaccine for children under five years old, because there’s not enough data on the efficacy of a third dose.
An FDA advisory panel meeting scheduled for next week has been postponed, the FDA said.
“Based on the agency’s preliminary assessment, and to allow more time to evaluate additional data, we believe additional information regarding the ongoing evaluation of a third dose should be considered as part of our decision-making for potential authorization,” the agency said in a statement.
The decision to extend the data submission and delay the advisory panel meeting pushes back the timeline for authorizing COVID-19 shots for kids under five, a major blow to parents of young kids.
The companies said they don’t expect to have three-dose protection data available until early April.
“Cases continue to accumulate according to the study protocol and more data are being generated because rates of infection and illness remain high in children of this age, especially due to the recent Omicron surge,” Pfizer said in a statement.
Pfizer earlier this month began applying for emergency use authorization of its vaccine in kids ages six months to four years old. But though the company said three doses will eventually be needed, the application was only for two doses.
At the time, Pfizer said it was applying before all the data were available at the request of the FDA, so the process of authorizing two doses could begin. The idea was that the authorization could then later be expanded to three doses once the data becomes available.
According to FDA, the goal was to understand if two doses would provide sufficient protection, and then authorize the eventual third dose later.
The delay likely indicates the agency did not have data that showed two doses was enough.
When asked directly during a press briefing if new data showed two doses did not provide sufficient protection, Peter Marks, head of the FDA division responsible for vaccine safety, did not directly answer.
“The 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 the determination that we could proceed with doing an authorization,” Marks said.
The companies and FDA said data was coming in rapidly because so many children have been infected with omicron
“Given that the study is advancing at a rapid pace, the companies 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. This is also supported by recent observations of three dose booster,” Pfizer said.
Pfizer and BioNTech said in December that the vaccine application for children under 5 could take as long as the middle of 2022, given that the immune response from two doses was not sufficient in children between 2 and 4 years old, and a third dose needed to be tested.
The doses in question for children under 5 are much smaller than the doses used for adults. According to the companies, data showed two doses may have been sufficient for children under the age of two.
Meanwhile, federal officials had already been planning how to distribute the vaccines. The Centers for Disease Control and Prevention this week told state and local health officials they could receive their first shipments by Feb. 21.
The FDA has been under enormous pressure to authorize a COVID-19 vaccine for the youngest children. Marks said the decision to delay should reassure them, because it means FDA is doing due diligence.
“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.
Still, Marks said he emphasizes with parents, and urged them to continue relying on whatever mitigation measures they have been using to keep their children safe.
“For the next few months, while these additional data are gathered, parents will have to rely on what they’ve come to do well, which is they’re using masking procedures, and they’re making sure that they’re vaccinated,” Marks said. “We will do our part, obviously, to move as fast as we can when we have the data but for now, we will have to ask parents to help to continue to do what they’ve been doing.”
This article originally appeared on TheHill