HealthFDA OKs mixing COVID vaccines; backs Moderna, J&J boostersBy MATTHEW PERRONE and LAURAN NEERGAARD (Associated Press)WASHINGTON Oct. 20, 2021 9:29 p.m.📨 Daily news in your inboxSign up today for OPB’s “First Look” – your daily guide to the most important news and culture stories from around the Northwest.EmailPlease leave this field blankSign up