States that recently announced plans to lift either indoor or school mask mandates have at least two things in common: Hospitalization rates are on the decline, and all except one have a larger share of fully vaccinated residents than the national average. Most of the governors in those states have linked these metrics to their moves to lift some Covid-19 mitigation measures. That's raising questions about whether these metrics should play a larger role in mitigation decisions nationwide -- more than Covid-19 case counts. Meanwhile, shifts to phase out state mask mandates conflict with the US Centers for Disease Control and Prevention's guidance to continue wearing masks in areas with "high" or "substantial" Covid-19 transmission, which includes about 99% of US counties.