Pfizer Inc and its German partner BioNTech SE said on Monday they have submitted an application to the U.S. Food and Drug Administration (FDA) for emergency use authorisation of their Omicron-adapted COVID-19 vaccine booster for children aged 6 months through 4 years.

If authorized, children would receive the primary series consisting of two doses of the original Pfizer-BioNTech COVID vaccine and one shot of the Omicron-adapted bivalent vaccine, the company said. The bivalent COVID-19 vaccine, which targets the original strain and the BA.4/BA.5 Omicron subvariants, is currently authorized as a booster dose for ages 5 years and older in the United States and the European Union (EU). Last month, a real-world study of more than 360,000 people in the U.S. found the updated bivalent boosters, including those of rival Moderna Inc, offered increased protection against new coronavirus subvariants in people who have received up to four doses of the older vaccine.