The CDC recently announced the updated guidance, citing new evidence that vaccinated people who get breakthrough infections could carry enough virus in their noses and throats to infect others.
COVID-19 vaccines greatly reduce the chance of severe illness and death and remain effective against variants, including the now predominant delta variant. But it’s still possible to get infected.
Masking could prevent the spread of the virus to children too young for vaccination and people with weak immune systems.
In short, the vaccine protects you. A mask protects others in case you are carrying the virus without knowing it.
You can find out your county’s level of coronavirus transmission at the CDC’s COVID-19 data tracker website. The CDC recommends indoor masking in areas where transmission is substantial or high. Those areas are marked in orange and red on the site.
The CDC also recommends indoor masks for all teachers, staff, students and visitors to schools, regardless of vaccination status.