::THE SLICE REPORT WITH MONA AUSTIN

(The Slice): On Tuesday the CDC announced that fully vaccinated people and students in grades K-12 must wear masks again when they return to in-person learning this fall. Masks are required in schools regardless of vaccination status. This mandate change was spurred by a surge in the Delta variant, a strand of the virus that mutates and duplicates itself for a faster spread. CDC Director Dr. Rochelle Walensky said the concern is that the Delta will render the current trio of available vaccines -- Moderna, Pfizer and J&J --ineffective. Because of this officials are urging everyone to #maskup in public indoor settings in parts of the country where the coronavirus has a "substantial or high transmission" rate which is now nearly two-thirds of U.S. counties. The dilemma is that not enough people got vaccinated to produce herd immunity and the science is showing the nation is deep diving into a worsening public health crisis. With this update, one thing remains ...