Des Moines Register: Every person in Iowa, vaccinated or not, should wear a mask when in public indoor spaces because of the level of spread of COVID-19, according to the Centers for Disease Control and Prevention. The CDC recommends the measure to stem the tide of the disease when there is substantial spread of the virus — 50 or more confirmed COVID-19 cases per 100,000 residents in the prior week, or a positive test rate of 8% or greater.