Hoping to prevent another school year from being upended by the pandemic, President Joe Biden visited a Washington middle school Friday to push his new COVID plan, accusing some Republican governors of being "cavalier" with the health of children.

Biden's plan, announced a day earlier, would require vaccinations for up to 100 million Americans and seek to ramp up virus testing. With those measures in place, he said, schools should present little risk for transmission of the coronavirus.

"I want folks to know that we're going to be OK," Biden said during an appearance at Brookland Middle School...