The data is in on school openings
Child infections in US up 129% after class resumed
America’s schoolchildren are weathering a third year of pandemic education, and most are in class together again instead of isolated at home.
Grown-ups battled over the right way to safely open schools amid a surge of a more transmissible variant of the COVID-19 virus. States and districts took wildly different approaches. Some strictly required masks; others banned mask mandates. Some states let districts decide.
Positive virus cases, quarantines and school closures sent kids back home in the early weeks of the fall semester, sometimes repeatedly. Millions of others remained in class.
“Schools are intertwined with everything that goes on in the community … just like the pieces of a machine,” said Doug Harris, an economist at Tulane University who’s studied the effects of school reopenings on COVID-19 hospitalizations.
The virus spreads at different rates in different communities, and vaccination rates, mask wearing and rules for behavior all play a role. School reopenings triggered changes in social behavior and health practices that influenced community spread, Harris said.
Many children were tested for the coronavirus more once they returned to school. Many parents returned to offices. Taken together, that meant more infections were captured that may have otherwise run their course undetected or unlogged.
“The increases that you were seeing in school-aged groups, what was happening is you had so many kids quarantined and parents were getting them tested,” said Jason Salemi, an epidemiologist at the University of South Florida. “You were just detecting a higher proportion of the cases that were out there.”
The highly contagious delta variant of the coronavirus was already surging as school started, further complicating the picture.
Some states have not reported all child deaths from COVID-19. Many districts decline to publicly report cases or quarantines.
But data from several sources can help us draw some conclusions about school reopening decisions.
The back-to-school season looked like it was headed for disaster. By early September, more than 1,000 schools had closed because of high numbers of students or staff in COVID-19 quarantines, according to data from Burbio, a company tracking districts’ responses to the pandemic.
Most of those schools have reopened because of increased COVID-19 protocols or the waning prevalence of the delta variant. The majority of students are in classrooms full time, regardless of their school’s mask or vaccine policy.
That’s good for students’ mental and social health – and crucial for their learning.
A total of 2,176 schools have partially or fully closed at some point this school year, or about 2% of the roughly 100,000 K-12 schools in
America, according to an analysis of Burbio data as of Oct. 20. Almost 1 million students were affected by these closures. (The data doesn’t account for all the students who quarantined while their schools remained open and may be an undercount in districts that do not share data publicly.)
Many kids who get COVID-19 don’t need to go to a hospital. Many don’t even have symptoms, though long-term effects are unclear.
COVID-19 case counts among kids spiked after their schools reopened. Data shows the growth rate for each state’s school-age kids was higher than among adults. (School start dates vary from district to district; for each state, USA TODAY used the start date of its largest school district.)
Doctors point to the start of school as the main cause of the surge in pediatric cases.
“Cases didn’t go up so much with the delta variant,” said David Buchholz, a professor of pediatrics at Columbia University’s Irving Medical Center. “They increased when school went back into session.”
Bryan Jarabek, a physician and chief medical informatics officer at M Health Fairview, saw the same trend in Minnesota. “It started right when we started school.”
Nationwide, cases in children grew by 129% in the six weeks after schools opened compared with the same period before classes started, according to a USA TODAY analysis of data from the Centers for Disease Control and Prevention.
Pediatric hospitalization rates were generally far lower in states with high numbers of vaccinated children.
The start of school was followed by faster COVID-19 growth in kids versus adults in most states, but the school effect tended to be more pronounced in places that banned schools from enforcing mask mandates or gave districts the ability to choose.
This analysis has limits. The same antimask-mandate states that saw the biggest pediatric surges also had lower vaccination rates at all ages. In other words, it’s hard to separate the two effects.
“Having a low vaccination rate was associated with greater hospitalizations, and having no mask was also associated with greater hospitalizations,” said Julie Swann, a professor at North Carolina State University who has advised school boards and health departments on the spread in schools.
Most states had a surge in pediatric hospitalizations tied to schools reopening, especially states that barred mask mandates. Together with the trend in cases, that suggests schools contributed to the spread.
Even states that mandated masks had bursts in pediatric cases and hospitalizations linked to the start of school. “Just having a mandate didn’t mean masks were worn or actually enforced,” said Jennifer Nuzzo, an epidemiologist at Johns Hopkins University who studies global health security policy.
Last summer, Gov. Ron DeSantis, a Republican, signed an executive order banning schools from requiring masks. Several districts flouted the order, and a court ruling in August put it on hold. In September, an appeals court ruled the ban on mandates could continue. A dozen or so school boards have continued to defy the ban and require masks.