CNN  — 

Moderna announced Thursday that it’s asked the US Food and Drug Administration for authorization for a second Covid-19 booster shot for everyone 18 and older.

Moderna is seeking an amendment of the FDA’s emergency use authorization for its Covid-19 vaccine to allow a fourth vaccine dose for any adults who’ve gotten an initial booster of any of the authorized or approved vaccines.

“The request to include adults over 18 years of age was made to provide flexibility for the U.S. Centers for Disease Control and Prevention (CDC) and healthcare providers to determine the appropriate use of an additional booster dose of mRNA-1273, including for those at higher risk of COVID-19 due to age or comorbidities,” the company said in a news release. “This submission is based in part on recently published data generated in the United States and Israel following the emergence of Omicron.”

On Tuesday, Pfizer and BioNTech, makers of the other mRNA Covid-19 vaccine used in the US, submitted a request to the FDA for EUA of an additional booster of their Covid-19 vaccine, but that application was only for adults 65 and older.

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A study of health care workers in Israel, published Wednesday in the New England Journal of Medicine, found that a fourth dose of the Pfizer/BioNTech or Moderna Covid-19 vaccine was safe and boosted antibody levels similar to what was seen after a third dose.

A few countries area already offering fourth doses of Covid-19 vaccines. Currently, fourth vaccine doses are authorized in the US only for certain people with weakened immune systems.

The FDA has said it will convene its independent vaccine advisers, the Vaccines and Related Biological Products Advisory Committee, in April “to have a transparent discussion about considerations for 2022 booster shots, including whether and when those boosters may be needed and for which populations, based on the available data and latest science on circulating or emerging virus variants.” A date for the meeting has not been set.