One early analysis of the CDC guidance suggests nearly 90% of people in the U.S. live in counties that fall into the two highest of five risk categories for reopening schools.

 

New CD Guidance for Reopening Schools Creates Color-Coded Risk Scale

...According to at least one early analysis of the CDC guidance, nearly 90% of people in the U.S. live in counties that fall into the two highest risk categories for reopening schools. The release of the guidance, which recommends aggressive thresholds, reignited a wave of criticism over the lack of federal guidance and left many wondering how many schools would have decided not to reopen for in-person learning if officials had this guidance earlier...

https://www.usnews.com/news/education-news/articles/2020-09-17/new-cdc-guidance-for-reopening-schools-creates-color-coded-risk-scale