The United States Center for Disease Control (CDC) has updated guidance for fully vaccinated people given new evidence on the B.1.617.2 (Delta) variant currently circulating in the United States. The new guidance recommends fully vaccinated people wear a mask in public indoor settings in areas of substantial or high transmission. The new guidance also advises fully vaccinated people to consider wearing a mask regardless of the level of transmission, particularly if they are immunocompromised or at increased risk for severe disease from COVID-19, or if they have someone in their household who is immunocompromised, at increased risk of severe disease or not fully vaccinated. The new guidance recommends fully vaccinated people who have a known exposure to someone with suspected or confirmed COVID-19 to be tested 3-5 days after exposure, and to wear a mask in public indoor settings for 14 days or until they receive a negative test result.
The CDC also recommends universal indoor masking for all teachers, staff, students, and visitors to schools, regardless of vaccination status.