(CNN) The nation's schools have been in an upheaval since the pandemic began. And now, amid a resurgence of Covid-19 cases, states are revisiting contingency plans to safely reopen them.
Several governors are taking sides in the debate between the push for attendance and the hesitation to gather kids before it's safe.
The US Centers for Disease Control and Prevention has guidelines for administrators and parents. But it's up to districts to decide the safest course, director Dr. Robert Redfield told CNN on Thursday night.
"We all want to protect the safety of the children that are in schools," Redfield said. "There's really a public health crisis. We are paying by not having these schools open, and I think we really need to get that balance."
President Donald Trump on Friday reiterated his school funding threat in a morning tweet. He has advocated for reopening states amid surging cases.
"Schools must be open in the Fall. If not open, why would the Federal Government give Funding? It won't!!!" he tweeted.
More than 90% of schools money comes from state and local levels, but schools receive targeted dollars from the US Department of Education. The money often affects the country's most vulnerable students.
Thursday brought 63,247 new Covid-19 cases in the US, a record for a single day, according to data from Johns Hopkins University. The new high comes as many states set records in infection rates and hospitalizations and 33 states saw an increase in new cases reported compared to last week.
Michigan Gov. Gretchen Whitmer told reporters the numbers will determine if the state has to go back a phase in its reopening plan, in which case students may not return to the classroom as currently planned.
Arkansas has pushed the first day of school back from August 13 to 24 to give districts time to adjust to a blended learning plan, Gov. Asa Hutchinson told reporters Thursday.
In Florida, with its particularly high instances of new cases and hospitalizations, Gov. Ron DeSantis weighed the increase of cases against the education gap that can come from students learning at home. If Home Depot and Walmart can be open, so can schools, he said.
And though the American Academy of Pediatrics ultimately wants students to be back in school, Florida's statewide mandate to reopen schools goes against its recommendations, President Dr. Sally Goza said in an interview Wednesday morning on NPR.
"We know that it has to be safe, and we know that we have to try to decrease that transmission as much as we can," Goza said.
Infectious disease experts want decisions on reopening schools to be "based on evidence and available resources to address risks of infection and illness," says a statement Friday from the Infectious Diseases Society of America and the HIV Medicine Association.
Children are less likely to develop serious illness due to Covid-19 and to transmit the disease, the statement says. But children have become seriously ill and some have died. That "should raise concerns, given that much remains unknown about the dynamics of the new coronavirus," said the statement from Dr. Thomas File, president of the Infectious Diseases Society of America, and Dr. Judith Feinberg, chair of HIV Medicine Association.
"We will not gain control of this pandemic or successfully reopen the economy unless we protect people and public health first," the statement said. "The safety of our children, their families, teachers and other school staff must be guiding factors in all school reopening decisions, and no school should be forced to open in a situation that presents unacceptable risks."
In the medical journal Pediatrics, two pediatric infectious disease specials wrote that adults, not children, appear to be key to spreading the coronavirus. Schools should give "serious consideration" to staying open even when the virus is spreading, they said. Schools "may be less important in community transmission than initially feared."
"Almost 6 months into the pandemic, accumulating evidence and collective experience argue that children, particularly school-aged children, are far less important drivers of (coronavirus) transmission than adults," said Drs. Benjamin Lee and William Raszka Jr. of the Larner College of Medicine at the University of Vermont.
Lee and Raszka wrote that children may have milder symptoms, releasing fewer infectious particles, or they may have had few opportunities to become infected, since many schools closed around the time physical distancing orders began.