On Mar. 29, 2022, Moderna announced that it had received approval from the U.S. Food and Drug Administration (FDA) for its amendment to the emergency use authorization (EUA) to allow for a second booster dose of its COVID-19 vaccine (mRNA-1273) at the 50 ﾵg dose level in adults 50 years of age and older who have received an initial booster of any of the authorized or approved COVID-19 vaccines and adults 18 years of age and older with certain kinds of immunocompromise.

The application to amend the EUA has been based on published data from Israel indicating the safety and effectiveness of administering a fourth dose of mRNA vaccine during the Omicron variant surge.