Covid risks that shut most in-person schooling, at least for a while, still exist nearly 18 months into the pandemic – though generally are lower because free shots can protect everyone over 12 and because children under 10 seem to be less likely to transmit the virus than adults and older students. So the federal Centers for Disease Control (CDC), the American Academy of Pediatrics (children's doctors) and many other experts agree that classrooms should open for the school year already under way in a some districts.

"We are in a very different place than we were a year ago," says Elizabeth Stuart, a disease specialist at Johns Hopkins University in Baltimore. "We have very effective vaccines [and] we know a lot more about how to open schools safely." Plus, it became clear that online learning or hybrid classes have big drawbacks.

But at the same time, a mutant (altered) form of the Covid virus called the Delta variant makes safety precautions in schools it even more critical, doctors say. It's unclear whether the new strain affects children more seriously than earlier forms. The good news is that vaccines give strong protection against the Delta variant, reducing the chance of being infected and guarding against the worst outcomes. Yet to be safe, the CDC two weeks ago recommended that everyone wear masks in schools this fall, even if vaccinated.

That creates tension between school boards and Republican governors in Texas, Florida, Iowa and Arizona. Public education officials in Phoenix said last week they will require masks, defying state law and Gov. Doug Ducey. "It was unconscionable and very short-sighted of our legislature and governor to take steps to ban mask mandates," said Kathy Hoffman, Arizona's elected superintendent of public instruction. In Florida, the huge district in Broward County last week dropped mask requirements just five days after the school board voted unanimously to make them mandatory. The whiplash came when Ron DeSantis gave the state power to withhold money from schools requiring masks. And in Iowa, Gov. Kim Reynolds signed legislation in May that blocks mask mandates in K-12 schools and bars cities or counties from requiring facial coverings in businesses. At the White House, President Biden showed frustration over governors opposing masks and vaccines: "If you aren't going to help, at least get out of the way of the people who are trying to do the right thing."

President says: "It's clear to me and to most of the medical experts [that] not allowing mask mandates in the schools [is] bad health policy." – Aug. 3

Doctor says: "When you have masks and even three-foot distancing, you are not going to see major outbreaks in schools." -- Dr. Yvonne Maldonado, a pediatric infectious-disease specialist at Stanford University in California

Governor says: "We really are strongly encouraging districts to adopt masking policies. It's an unfortunate part of the moment that we're in, but this variant is a real concern." – Gov. Gretchen Whitmer, D-Mich.