The public health emergency may be over, but COVID-19 cases and hospitalizations are back on the rise as the winter cold and flu season approaches and school is back in session.
Experts say families and schools can stay healthy by going back to basics -- hand washing, ventilation, vaccines, masking and staying home when needed -- and that schools should be prepared to respond to possible outbreaks.
More than 6.5 million children miss 15 days of school or more per year, according to the American Academy of Pediatrics. School absenteeism has been linked to a number of negative health and socioeconomic outcomes.
So far this school year, at least two school districts have had to cancel classes due to respiratory illnesses in Texas and Kentucky.
"We know that healthy students are better learners and that kids who have the opportunity to be in school and engaged with their education are healthier both from a physical health standpoint, but also from a mental and developmental standpoint," Dr. Katherine Connor, M.D., M.S.P.H, medical director at the Johns Hopkins Rales Health Center, told ABC News.
But kids aren't the only ones present in school and others around them are impacted during the respiratory virus season.
"I like to think of the school as its own ecosystem," Dr. Peter Hotez, M.D., Ph.D., co-director of the Texas Children's Hospital Center for Vaccine Development and dean of the National School of Tropical Medicine at Baylor College of Medicine, told ABC News. "When we talk about keeping our kids safe in school, remember, yes, of course, it's the kids but it's also in many cases the parents who may have underlying health conditions. How do we keep them safe, because kids will bring home illness from the schools, and also how do we keep the school teachers safe?"
Over the past three years, there have been questions and criticisms about how schools should operate during the public health emergency, including debates about masking and distance learning. Now that the public health emergency is over, precautions are left up to local schools and jurisdictions, or for people to decide individually.
ABC News spoke with five experts about what they recommend schools, parents and caregivers do to best protect everyone's health.
"Masks did actually decrease transmission of this virus, however, we've had to be practical and cognizant of the current situation, that asking kids or schools to implement masks universally may not be feasible," said Dr. Diego R. Hijano, M.D., M.Sc., infectious disease specialist at St. Jude Children's Research Hospital. "You may want individually or as a parent to try to put a little bit more emphasis [on this] if you're at risk -- to try to protect yourself or your kids by using a mask or sending your kids who are vulnerable with masks to school."
MORE: The best way to protect you and your family this flu seasonExperts say groups at higher risk of complications from respiratory viruses include very young infants, especially those too young to receive certain vaccines, the elderly, and the immunocompromised.
Hotez says masking could be a good consideration as rates of COVID-19 continue to increase, "especially to protect both parent, both students, teachers and the kids when they return home."
Some schools have opted to invest in updating the air quality.
Sandra MacArthur, superintendent of a small school district in Maine, told ABC News that improving the HVAC system in schools was their first priority. She said she believes it helped keep the schools open to in-person learning throughout the pandemic, from September 2020 onward.
"I think in-person learning is by far the best that we can deliver to our students," MacArthur said. "The remote [learning] played a role and will continue to play a role, but we want our children here."
While improved air quality offers a longer-term solution that could have benefits beyond reducing the spread of infections in schools, there are still challenges for many schools including cost, time and resources. MacArthur said prior to receiving federal funding, updating their HVAC system was cost-prohibitive.
MacArthur said her schools still keep hand sanitizer available in every classroom.
Routine hand washing is a healthy move applauded by doctors like Katie Lockwood, M.D., M.Ed, spokesperson for the American Academy of Pediatrics and pediatrician at Children's Hospital of Philadelphia.
"[Kids] should be washing their hands anytime that they use the bathroom, if they cough or sneeze into their hands, touch anything that feels kind of gross to them or that they think lots of other people have touched, and before they're eating," Lockwood said. "Make [handwashing] something that families practice at home as well, so that it becomes really a natural part of their routine."
This year's flu shots are available for anyone at least 6 months old and early data shows they are effective against the strain of flu that is already circulating in South America, which is also expected to circulate here in the U.S.
The U.S. Food and Drug Administration and Centers for Disease Control and Prevention have also greenlit updated COVID shots for anyone 6 months and older. And for the first time ever, people 60 and older can get an RSV vaccine.
"I think the single most impactful thing that that we should be thinking about is taking this new annual [COVID] immunization," Hotez said. "I think that's going to be especially important for the adults for the parents and for the school teachers, but I think there's also benefit for immunizing the children as well."
MORE: Ahead of a possible 'tripledemic,' pediatrician shares what to know about getting kids vaccinatedFrom Aug. 1, 2021 to July 31, 2022, COVID-19 lead to more deaths among kids and young adults 0-19 years old than any other infectious or respiratory disease compared to 2019, according to research published in the Journal of the American Medical Association.
"Parents should consider getting their children the updated COVID vaccine as soon as its available," said Dr. Alok Patel, M.D., ABC News contributor and pediatrician at Stanford Children's Health. "And to make it easier, get the vaccine in the same appointment as the flu shot."
"It's really important that families do what they can to prevent the things that we do have vaccines for," Lockwood said.
Experts agree that staying home when someone is sick is important to stop or slow the spread of infections, but isn't always easy -- so primary prevention is still key to keeping kids in school using tools like vaccines.
"One most important thing that is very difficult for us parents to accomplish is to keep your kids at home when they are sick. Because everything starts when somebody comes sick to the workplace or to the school where the virus transmits," Hijano said.
"We're walking this delicate line of making sure that kids are erring on the side of attending school as much as possible, while also making sure that if your child really is sick enough to spread infection to other kids, that they're being cautious, talking with their health care provider and sort of making a wise decision whether or not to go to school that day," Connor explained.
"Keeping your kids [home] if they're sick not only helps them get better quicker, it keeps other students safe as well," Patel added.
"I would also encourage parents to have a conversation with their children's school to learn about COVID and infectious disease protocol, about ventilation, sick day policies, all of it," Patel said. "This will better prepare parents for anything that comes their way."
Said Lockwood, "Guidelines do change as we learn more and each season, we see what the viruses are doing … and that's something that we don't often know until the season starts,. I think flexibility is really the thing that we've all learned more of during the pandemic and from the pandemic."
Dr. Jade A Cobern, M.D., M.P.H. is a licensed and practicing physician and a member of the ABC News Medical Unit.