On Apr. 28, 2022, Moderna announced that it had submitted a request for emergency use authorization (EUA) for its COVID-19 vaccine (mRNA-1273) in children 6 months to under 2 years and 2 years to under 6 years of age to the U.S. Food and Drug Administration and that similar requests are underway with international regulatory authorities. The requests were based on a 25 ﾵg two-dose primary series of mRNA-1273.

A 50 ﾵg booster dose of mRNA-1273.211 demonstrated superiority against Beta, Delta and Omicron variants of concern one month after administration. Superiority continued six months after administration for Beta and Omicron variants of concern as well. A 50 ﾵg booster dose of mRNA-1273.211 was generally well tolerated with a reactogenicity profile comparable to a booster dose of mRNA-1273 at the 50 ﾵg dose level. The manuscript was available as a preprint through Research Square.