Both are bivalent vaccines that combine the companies’ original vaccine with one that targets the BA.4 and BA.5 Omicron sublineages. Both companies submitted applications to the FDA for emergency use authorization for their updated vaccines last week.
Pfizer’s updated vaccine is a 30-microgram dose authorized for people age 12 and older. Moderna’s updated vaccine is a 50-microgram dose authorized for people age 18 and older.
The shots can be administered only after they’re recommended by the US Centers for Disease Control and Prevention. The CDC’s vaccine advisory group is scheduled to vote Thursday on whether to support recommending the boosters for use.