BA.2 subvariant now the dominant strain of COVID-19 in the U.S. Mar 30, 2022 12:24 PM EDT ABC News, ABC NEWS– The Centers for Disease Control and Prevention has signed off on a second booster shot for people over 50, and the BA.2 subvariant is now the dominant strain in the U.S. ABC’s Eva Pilgrim has more. Categories: National News Tags: booster shots, CDC ShareFacebookTwitterPinterest