Moderna’s vaccine is safe and 94% effective, regulators say. The analysis by the Food and Drug Administration’s (FDA) means it could become the second coronavirus vaccine to be allowed in the U.S.

The 54-page report said there were “no specific safety concerns” and that serious adverse reactions were rare. It comes one day after Americans across the country began receiving jabs of the Pfizer-BioNTech vaccine.

Endorsement of the Moderna vaccine by FDA scientists was announced on Tuesday, two days before the vaccine panel meets to discuss emergency approval.