By Marie Rosenthal
The FDA amended its emergency use authorizations of the Moderna and Pfizer-BioNTech COVID-19 vaccines to allow bivalent formulations to be used as a single booster dose at least two months after primary or booster vaccination.
The updated boosters contain two messenger RNA (mRNA) components of the SARS-CoV-2 virus to provide better protection against the omicron variant, the agency said. The 50-mcg booster dose of Moderna mRNA-1273.222 includes 25 mcg of mRNA encoding for the