(WWLP) – Pfizer now hopes to tell U.S. regulators how well its COVID-19 vaccine works in young children by early June.

Currently, only children ages 5 or older can be vaccinated in the U.S., using Pfizer’s vaccine.

Moderna hopes to be the first to offer vaccinations to the youngest children and began filing its data with the FDA last week.

The FDA has set tentative meetings in June to review data from one or both companies.