CDC recommends universal indoor masking for K-12 schools Duval County Public Schools says it’s consulting with health department about new guidance Updated: July 27, 2021 10:47 pm CDC recommends universal indoor masking for K-12 schools The Centers for Disease Control and Prevention on Tuesday recommended universal indoor masking for all teachers, staff, students and visitors to K-12 schools, regardless of vaccination status. That recommendation came as the CDC also recommended that fully vaccinated people wear masks in public indoor settings in areas of substantial or high transmission of COVID-19, changing course from its guidance in May that said fully vaccinated people could stop wearing masks outdoors in crowds and in most indoor settings.