Check the transmission rate in your community

To prevent further spread of the Delta coronavirus variant, the US Centers for Disease Control and Prevention updated its mask guidance on Tuesday to recommend that people who are fully vaccinated wear masks indoors if they are in areas with “substantial” or “high” transmission of Covid-19, which includes more than half of all US counties. 

Nearly half – 46% – of US counties currently have high transmission and 17% have “substantial” transmission, according to CDC data as of Tuesday morning.

In two states, Arkansas and Louisiana, every county is currently listed as having “high” levels of community transmission of Covid-19, according to CDC data. Several other states – including Missouri, Mississippi and Alabama – also have “high” transmission in nearly every county. In Florida, every county was listed with high transmission on Monday; as of Tuesday morning, one – Glades County – has substantial transmission

Meanwhile, the guidance for people who are unvaccinated remains the same: continue masking until they are fully vaccinated.

The CDC’s latest guidance also recommends that community leaders encourage vaccination and mask-wearing to prevent further outbreaks in areas of substantial and high transmission. The agency recommends that local jurisdictions encourage universal indoor masking for all teachers, staff, students, and visitors to schools, regardless of vaccination status.

Some background: Earlier this month, the CDC’s Covid-19 school guidance noted that fully vaccinated people do not need to wear masks, and then about a week later the American Academy of Pediatrics issued stricter guidance recommending that everyone older than age 2 wear a mask in schools, regardless of vaccination their status. Now the updated CDC guidance recommends everyone in schools wear a mask.

The last time the CDC updated its mask guidance was two months ago, to say most people who are fully vaccinated could go without masks indoors. That guidance moved so quickly that administration officials were informed less than a day before – and many public health experts were taken by surprise. This time, the CDC’s updated guidance has been expected for a few days.

As the highly contagious Delta coronavirus variant continues to circulate across the United States, top federal health officials debated whether to issue new guidance on masks, meeting on Sunday night to review new data and evidence regarding the transmissibility of the variant and breakthrough cases among vaccinated people, according to a person familiar with the meeting.

The CDC emphasized on Tuesday that while some breakthrough cases have occurred, getting vaccinated still prevents severe illness, hospitalization and death. The CDC also noted that the highest spread of Covid-19 cases and severe outcomes is happening in areas with low vaccination rates and among people who are unvaccinated.