Pfizer and its partner BioNTech on Thursday officially submitted a request to the US Food and Drug Administration for their COVID-19 vaccine to be used in children 5 to 11.

Last month, Pfizer said topline results from its clinical trial showed its COVID-19 vaccine was safe and effective in children ages 5 to 11. In a series of tweets on Thursday, Pfizer said it’s “committed to working with the FDA with the ultimate goal of helping protect children against this serious public health threat.”

The Pfizer-BioNTech vaccine was fully approved by the US Food and Drug Administration for people 16 and older in August, but is still under emergency use authorization for kids 12 to 15. Pfizer remains the only vaccine authorized for use in kids as young as 12 in the US.

In anticipation of the formal submission, the FDA last week scheduled an advisory committee meeting for Oct. 26 to discuss the use of Pfizer’s COVID-19 vaccine in children ages 5 to 11.

“We know from our vast experience with other pediatric vaccines that children are not small adults, and we will conduct a comprehensive evaluation of clinical trial data submitted in support of the safety and effectiveness of the vaccine used in a younger pediatric population, which may need a different dosage or formulation from that used in an older pediatric population or adults,” said Janet Woodcock, acting FDA commissioner, in a release.

With many kids back in classrooms, the US has seen a wave of COVID-19 cases in children, according to the American Academy of Pediatrics. There were nearly 850,000 child cases added over the past four weeks. As of Sept. 19, 56% of kids 12 to 17 have received at least one dose of the COVID-19 vaccine, according to the AAP.

Clinical trials for Moderna and Pfizer vaccines in even younger children are underway. Last month, Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Disease, said in an interview with ABC11 that it’s “very likely” COVID vaccines will be available for kids as young as 5 and 6 “as we get into October and early November.”