Schools are bracing for what could be a nasty flu season -- and for principals and educators, that may mean making tricky decisions about when to close their doors.
The challenge is to balance preventing the spread of the deadly swine flu virus with the potential for causing massive disruptions for families and students.
Watch "World News With Charles Gibson" tonight at 6:30 ET for the full report.
"How do you continue learning for students who are healthy?" asked Cindy Ball, director of community relations for Rockdale County Public Schools in Georgia, where schools are already back in session. "If you have to close the school, how do you continue learning?
"We don't have any magical answers," Ball said.
To help educators face the upcoming season, the government plans to release guidelines as early as Friday to help school districts manage potential closings.
But while federal officials can give advice, they know decisions need to be made locally.
"If we find that we're in a position where we need to close the schools, we'll have that discussion with our local board and our local community, and do what's right for our students," Ball said.
"Schools' nurses in our county have taken an active role along with our county public health department, and we've gone out to provide school-based flu clinics," Sheri Coburn, director of comprehensive health programs at the San Joaquin County Office of Education in California, said today.
Today, John Barry, author of "The Great Influenza," said guidance from the government makes sense.
"Keeping kids at home for days at a time, much less weeks, is almost impossible," he said. "When you add to that the burden imposed on working parents, and getting meals to poor students who depend on school for them, only in extreme circumstances does closing schools make sense."
A decision to rethink the advice offered to schools comes in part to extensive closures last spring. In May, the administration urged schools to shut down to stop the spread, and hundreds did -- affecting half a million students. But within weeks, the Centers for Disease Control and Prevention (CDC) revised its lesson plan.
"Advice about school closings has changed as we have learned more about H1N1 influenza and also as the outbreak has progressed," Dr. William Schaffner, professor and chairman of the department of preventive medicine at Vanderbilt University School of Medicine, said today.
"Now that the severity is akin to seasonal influenza, there is less need to close schools and less local support for such a policy," he added. "School closings produce hellacious disruptions."
Still, schools could face a daunting challenge as they prepare to reopen after summer break. Unsurprisingly, health officials last week announced that school children would be among those who take first priority for a swine flu vaccine. People who care for infants under six months of age, health care and EMS workers, pregnant women and anyone under the age of 64 with underlying medical conditions join children, teenagers and college students on that list.
Fifty percent of swine flu cases so far have been among people between the ages of 5 and 24, according to the latest numbers from the CDC.
Dr. Howard Markel, a pediatrician at the University of Michigan, told ABC News today that the fact that kids are more affected than adults is cause for concern. He added that among groups of students also at risk for problems like asthma or diabetes there may be added need to fine-tune closure plans.
Markel also said school closures are promising when the situation is severe but that the current threat so far doesn't merit mass closures.
"You have to make sure that the threat merits the response," he said.
Visit the ABC News OnCall+ Swine Flu Center to get all your questions answered.
Swine Flu Vaccine Clinical Trials Begin This Month
Of all cases in the U.S., more than 5,500 people have been hospitalized and 353 have died.
Put into context, the regular seasonal flu kills about 36,000 people nationwide every year. But it usually hits older people harder than young people -- whereas the opposite holds true for swine flu.
To help prevent a surge of sick students, teachers and others, clinical trials for a vaccination are starting this month, expected to be followed by a voluntary vaccine program.
Those vaccinations were initially anticipated to begin mid-October, but last week health officials expressed some concern about whether that timeline will hold. Data from the trials may not be ready for scientists to review until the end of September, and it could take another four to six weeks to begin a vaccination program. That could mean the start of the vaccine program gets pushed back into November -- months after the start of school.
Last week, the Government Accountability Office (GAO) issued the latest in a series of warnings saying "gaps remain at all levels of government" when it comes to planning for a possible pandemic flu.
"Further actions are needed to address the capacity to respond to and recover from an influenza pandemic, which will require additional capacity in patient treatment space, and the acquisition and distribution of medical and other critical supplies, such as antiviral and vaccines," the GAO report said.
School are nonetheless trying to prepare for what could lie ahead.
"I think there's more of an awareness going into this school year," Ball said. "We certainly know that we have a lot of preparation to do and a lot of planning to do."
Coburn said, "We just want to make sure that kids are washing their hands along with parents and staff, and that we work together, as far as public health, parents, and school communities to make sure that children take preventative actions."
Ball has basic tips: "When you don't feel good, stay home. If you have a temperature, stay home. Don't participate in your sports when you're running a fever."
"The early days of the H1N1 outbreak have passed," said Schaffner. "Over 1 million cases have occurred in the U. S., and the virus now is well-embedded in our communities. School closings can no longer be seen as an effective means of limiting transmission."
ABC News' Olivia Hallihan, Courtney Hutchison and Dan Childs contributed to this report.