Government Executive email 1 in 4 Unvaccinated People May not Comply with CDC Guidelines to Wear Masks Indoors, Survey Suggests Some vaccinated people will still be wearing masks to protect themselves from people who may not be vaccinated or wearing masks. Matt Motta , The revised guidelines on when and when not to wear masks came as a surprise to many Americans. The Centers for Disease Control and Prevention announced May 13, 2021, that people who are fully vaccinated against COVID-19 can safely enter many indoor settings, such as grocery stores and restaurants, without wearing a mask. The CDC’s updated guidelines also ask that unvaccinated or partially vaccinated people continue to wear a mask – even in establishments like bars and restaurants, where doing so may no longer be required.