CDC Reverses Course on Masks for Fully Vaccinated in Light of SARS-CoV-2 Variants

The CDC also issued a health advisory about the urgent need to increase COVID-19 vaccination coverage.

Concerns over the highly infectious Delta variant (B.1.617.2) have prompted the CDC to reverse course and recommend that individuals fully vaccinated against COVID-19 wear masks indoors in public if they are in an area of substantial or high transmission.

Fully vaccinated individuals with weakened immune systems or who are increased of severe disease might also choose to wear a mask indoors regardless of transmission level.

The recommendations were part of a new guideline on implementing COVID-19 prevention strategies that was recently published in the CDC’s Morbidity and Mortality Weekly Report (MMWR). According to the CDC’s COVID-19 Response Team, factors that should inform the need for additional layered prevention strategies include SARS-CoV-2 community transmission level, health system capacity, vaccination coverage, capacity for early detection of cases, and populations at risk for severe disease.

The CDC has also issued a health advisory about the urgent need to increase COVID-19 vaccination coverage to avoid surges of new infections that may overwhelm healthcare capacity. According to the agency, unvaccinated individuals account for most of the new COVID-19 infections, as well as hospitalizations and deaths.

To support vaccination efforts, the CDC is urging unvaccinated clinicians and support staff to get vaccinated as soon as possible. In addition, clinicians should increase their outreach efforts to encourage COVID-19 vaccination among their patients.


  1. Christie A, Brooks JT, Hicks LA, et al. Guidance for implementing COVID-19 prevention strategies in the context of varying community transmission levels and vaccination coverage. MMWR Morb Mortal Wkly Rep. Published July 27, 2021. doi: icon
  2. Vaccination to prevent COVID-19 outbreaks with current and emergent variants — United States, 2021. CDC Health Alert Network Health Advisory. Published July 27, 2021.