Pfizer Inc. (NYSE:PFE) and BioNTech SE (Nasdaq: BNTX) have filed paperwork with the European Medicines Agency (EMA) requesting permission to use the Comirnaty COVID-19 vaccine in children aged 6 months to 5 years old.

As in the U.S., the companies are attempting to win authorization for a 3-µg dose vaccine administered as a three-dose series.

On June 17, FDA authorized the use of the Pfizer-BioNTech and Moderna vaccines in children as young as six months in the U.S. Before that, an FDA advisory committee unanimously supported the authorization of the Pfizer and Moderna vaccines in young children.

The EMA request included data from a Phase 2/3 randomized, controlled study based on data from 4,526 children 6 months to less than 5 years of age.

The study found that three doses of the vaccine resulted in a robust immune response with a safety profile similar to a placebo. In addition, the companies noted that adverse events were less common in young children than those between the ages of 5 and 12.

PFE shares were flat in mid-day trading, hovering around $53.15. BNTX shares were down 1.31% to $167.90.