Every county in the Chicago area is seeing "substantial" or "high" community transmission of COVID-19, placing the entire region in the category in which fully vaccinated people should resume wearing a mask indoors, federal health officials say.
The Centers for Disease Control and Prevention updated its guidance last week to recommend that fully vaccinated people wear masks in indoor settings again in areas of the U.S. that are seeing "substantial" or "high" transmission of COVID-19.
The new guidance marked a reversal from earlier recommendations that said fully vaccinated people could remove masks in most settings.
So in which areas is the CDC advising people wear masks indoors? The agency points to its COVID-19 data tracker showing levels of community transmission, along with other data, for each county in the U.S.
As of Tuesday, 97 of Illinois’ 102 counties - including all counties in the Chicago area - were experiencing either “substantial” or “high” levels of community transmission, triggering the recommendation to mask indoors, regardless of vaccination status.
The agency uses two measures to group U.S. counties into the four levels of community transmission: the number of new cases per 100,000 residents and the percent of COVID-19 tests that are positive over the past week.
If a county has reported 50 to 100 cases per 100,000 residents over a seven-day period or has a positivity rate of 8% to 10%, it falls into the "substantial transmission" tier, while those reporting 100 cases or more per 100,000 or have a positivity rate of at least 10% are labeled as "high transmission." Those are the two groups for which the CDC recommends mask-wearing.
The CDC also said last week that fully vaccinated people also "might choose to mask regardless of the level of transmission, particularly if they or someone in their household is immunocompromised or at increased risk for severe disease, or if someone in their household is unvaccinated."
The Illinois Department of Public Health said last week that it is "fully adopting" the CDC's updated guidance and following federal health officials' lead in recommending masking indoors at K-12 schools universally among teachers, staff, students and visitors to schools, regardless of vaccination status.
Then on Wednesday, Gov. J.B. Pritzker announced a new mask mandate, requiring - rather than recommending - that all students, teachers and staff in K-12 schools wear masks while indoors as officials take steps to try to slow the spread of the more transmissible delta variant.
Pritzker said that the new requirement will take effect immediately, and will also apply to all students and coaches participating in indoor sports and other activities.
"As your governor, it's my duty to say that we must all take immediate and urgent action to slow the spread of the delta variant," he said. "People are dying who don't have to die."
Pritzker added that the state has a "limited amount of time" to slow the spread of the delta variant.
State employees who work in congregant care facilities, veterans' homes and correctional facilities will also be required to receive COVID-19 vaccinations, according to the governor.