For a moment, it seemed as if the worst of the COVID pandemic was over in the U.S., thanks to the introduction of highly effective vaccines. Unfortunately, the Delta variant changed the game quickly, resulting in a new surge of cases, hospitalizations, and deaths. Now, places across the U.S. are implementing new COVID restrictions, and health experts say they're instituting their own precautions against this fast-spreading variant. Recently, the Centers for Disease Control and Prevention (CDC) also released new guidance to help protect people, vaccinated and not, from COVID. And at this point, it applies to nearly the entire country.
On July 27, the CDC reversed its mask recommendations, asking that anyone—even those fully vaccinated—mask up indoors in areas that have substantial or high COVID transmission. The agency updates its data every Monday to show what counties had these levels of community transmission over the previous week. Substantial transmission is considered 50 to 100 weekly cases per 100,000 people or a positivity rate between 8 and 10 percent, while high transmission is 100 or more weekly cases per 100,000 people or a positivity rate of 10 percent of higher.
Over the last few weeks, the virus has spread significantly through the country during the Delta variant surge. The CDC's data from Aug. 9 shows that 2,890 countries in the U.S. have substantial or high spread right now. The amount of counties that have reached a high level of community transmission increased by more than 12 percent in just seven days.
According to CNN's analysis of this data, around 98.2 percent of the U.S. population now live in counties with spread high enough to fall under the CDC's recently updated mask guidance. That means that all but six million people in the U.S. should be masking up indoors right now, regardless of vaccination status.
"To maximize protection from the Delta variant and prevent possibly spreading it to others, wear a mask indoors in public if you are in an area of substantial or high transmission," the CDC states on its website.
In states like South Carolina, Georgia, Tennessee, Florida, Mississippi, Arkansas, and Louisiana, all counties have high transmission—meaning every resident in these states should be masking up. Residents in other states like New Mexico, New Jersey, Connecticut, and Washington should be wearing masks as well, as all of these states' counties have either substantial or high spread.
According to the agency, the change comes amid new science, which suggests that vaccinated people infected with the Delta variant can spread the virus to others. The CDC also says that people who are immunocompromised or at increased risk for severe disease—as well as those with people in high-risk categories or unvaccinated individuals in their households—should consider wearing masks regardless of community transmission levels.
"As we follow the science and the science changes because the variant changes, we have to update our recommendations. It is not well-received—Americans do not want to receive a message that we need to be masking up again," CDC Director Rochelle Walensky, MD, said during an Aug. 3 interview with NPR. "But it is the safest thing to do right now, and that is what I promised the American people I would do to keep them safe