Moderna announced that it has 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 at the 50 µg 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 FDA's endorsement of a second booster dose will allow millions of Americans to build and maintain protection against SARS-CoV-2," said Stéphane Bancel, Chief Executive Officer of Moderna. "The virus continues to evolve, and we are currently on the verge of another potential wave driven by the BA.2 variant. Data continue to show that mRNA boosters remain the best defence against severe infection and death, and vaccines are a foundational part of our public health protection. Now, healthcare providers have the opportunity to advise higher-risk people about when and how to get boosted and build immunity in advance of future outbreaks."

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

On January 31, 2022, the U.S. FDA approved the Biologics License Application (BLA) for SPIKEVAX (Covid-19 Vaccine, mRNA) to prevent Covid-19 in individuals 18 years of age and older. Previously, Moderna's Covid-19 vaccine was available under EUA in the U.S. from December 18, 2020. A booster dose of the Moderna Covid-19 vaccine at the 50 µg dose level is authorized for emergency use in the U.S. under EUA for adults 18 years and older. A third dose of the Moderna Covid-19 vaccine at the 100 µg dose level is authorized for emergency use in immunocompromised individuals 18 years of age with certain kinds of immunocompromise.