“We are pleased to be able to submit data to regulatory authorities for this group of school-aged children before the start of the winter season,” said BioNTech CEO Ugur Sahin in a statement. The company said tests on that age group had produced results consistent with those in older populations.

It is now more than four months since the U.S. Food and Drug Administration (FDA) granted emergency authorization for the use of Pfizer/BioNTech’s Comirnaty vaccine in children between the ages of 12 and 15 (the jab also now has full FDA approval for people age 16 and older).

There are several considerations that the drugmakers have had to take into account when trialing the substance in younger children, one of which is the amount that is to be administered. In the case of Pfizer and BioNTech’s vaccine, kids between the ages of 5 and 11 will get 10-microgram doses, which is a third of the amount that people age 12 and older get.

In the statement, Pfizer CEO Albert Bourla said his firm was particularly glad to be able to provide protection to younger children because of the spread of the coronavirus’s Delta variant, which is causing more sickness at those ages than earlier strains had done.

“Since July, pediatric cases of COVID-19 have risen by about 240% in the U.S.—underscoring the public health need for vaccination,” Bourla said. “These trial results provide a strong foundation for seeking authorization of our vaccine for children 5 to 11 years old, and we plan to submit them to the FDA and other regulators with urgency.”

Pfizer and BioNTech’s Phase II/III study, which is taking place in the U.S., Finland, Poland, and Spain, includes children as young as 6 months of age.

The companies said they expect to provide results for the 2- to 5-year-old and 6-months to 2-year-old cohorts “as soon as the fourth quarter of this year.” These cohorts are getting doses of just three micrograms.