RELATED: These 4 States Are Seeing the Worst COVID Surges Right Now. While some kids have been back in school already, many schools wait till after Labor Day for the start of the school year. Tina Tan, MD, a professor of pediatrics at Northwestern University, told CNN that with students back to in-person learning, the risk of COVID outbreaks in schools without mitigation measures is significant. “One thing we saw earlier in the month of August is that there were many schools that opened but didn’t have mask mandates in place and were not using protective mitigation protocols,” Tan said. “We saw a number of outbreaks that happened in those situations where the school opened and then closed like a week later because there were so many teachers and students that got infected.” Tan hopes that when schools return after Labor Day, the schools that once didn’t take precautions “will be smarter, and they’ll have mask mandates in place and use protective mitigation protocols in order to prevent the potential to have future outbreaks occur in the school setting.” She acknowledged that it’s inevitable some COVID cases will occur, but she reiterated to CNN that there are a handful of simple mitigation methods that could limit the spread. Experts note that the ability for schools to stay open safely also depends on people outside of the school. The amount of virus circulating in the area, vaccination rates, and whether the community adheres to mitigation strategies can influence the amount of spread in schools as well, Noelle Ellerson Ng, associate executive director of advocacy and governance for the School Superintendents Association, told CNN.ae0fcc31ae342fd3a1346ebb1f342fcb “It is about the decisions the schools are making, and whether or not they’re going to be able to do any physical or social distancing, or whether or not they have masks in place—but schools are a microcosm of the broader community too,” Ng said. “What’s your vaccination rate in the eligible population? What is the general practice of broader mitigation strategies in the community? All of that is interrelated. The work of opening schools doesn’t occur in a silo.” RELATED: For more up-to-date information, sign up for our daily newsletter. White House COVID adviser Anthony Fauci, MD, told CNN on Sept. 7 that to protect children, especially those too young to be vaccinated, “you want to surround the children with people who are vaccinated,” including teachers and school staff. Fauci said we should also be protecting unvaccinated children with “universal masking” in schools. These calls to action on behalf of vulnerable children come after cases among young people surged over the past month. A study published by the Centers for Disease Control and Prevention (CDC) on Sept. 3 found that hospitalizations among children were four times higher in states with low vaccination levels as compared to states with higher vaccination levels. When schools started up in August without mask measures in place, these reopenings resulted in significant COVID outbreaks. A recent report from the American Academy of Pediatrics (AAP) found that during the week ending Aug. 26, one in five of the weekly reported COVID cases were children. According to the report, 203,962 children were diagnosed with COVID between Aug. 19 and Aug. 26. At the beginning of the pandemic, children only represented 14.8 percent of total cases. Now, children account for 22.4 percent of total COVID cases. RELATED: These States Will Be Hit by a “True Delta Wave” Next, Virus Expert Warns.