Pfizer Inc. and BioNTech SE filed a request within the United States Food and Drug Administration (FDA) on Monday, hoping to get approval for a COVID-19 Omicron vaccine booster for children under the age of 4.

The American pharmaceutical giant said in a statement that, if approved, children between the ages of 6 months and 4 years old would be able to get two doses of the original Pfizer-BioNTech vaccine and one dose of the Omicron-adapted bivalent vaccine.

In September, the European Union and the United Kingdom greenlighted the coronavirus Omicron vaccine has been approved as a booster dose for children. The United States also approved the use of bivalent COVID-19 vaccines made by Pfizer/BioNTech and Moderna as boosters for children down to five years of age.