Moderna is asking federal regulators for an emergency authorization of its mRNA covid-19 vaccine for those between 6 months and 5 years old. No vaccine has yet been approved for very young children in the U.S., which is a population of approximately 18 million people.

The emergency authorization request to the U.S. Food and Drug Administration will be completed by next week, the company said. If approved, it will be sent off to the U.S. Centers for Disease Control and Prevention for a vote and further authorization from the agency’s director.

The New York Times reported that Dr. Peter Marks, who heads the FDA’s vaccine regulation, said in a senate hearing Tuesday he might consider all vaccine doses for people under 18 years old as a whole. Hearings for this and other authorizations likely won’t happen before June, according to the Times.