(NEW YORK) -- Thanks to regular, strategic COVID-19 testing, over a dozen Utah high schools were able to save more than 100,000 days of in-person learning this winter and likely helped reduce spread of the virus, a recent analysis from the Centers for Disease Control and Prevention found.
As schools prepare to have more students in-person in the fall, health experts say strategic testing will continue to play a major role in helping to reduce transmission and keep doors open, especially if other mitigation measures, like physical distancing, are reduced.
Utah has been recognized as an early adopter of COVID-19 testing as a mitigation strategy in schools. Its testing strategies have been "hugely successful," Kendra Babitz, the COVID-19 state testing coordinator at the Utah Department of Health, told ABC News.
"We were really excited to highlight the success of these strategies, amid all of the chaos and lots of work that was required to bring them into fruition," Babitz said.
'Framework' for other states
The health department has helped implement COVID-19 testing programs in nearly all of Utah's 193 public high schools since November. One -- dubbed "Test to Play" -- requires students to get tested every 14 days to participate in extracurricular activities. The other, called "Test to Stay," calls for school-wide testing if the number of positive cases reached a certain threshold, instead of shifting to remote learning, in an attempt to limit disruptions to in-person instruction. The programs use rapid antigen nasal swab tests, which are less sensitive and cheaper than PCR tests but provide results faster, in 15 minutes.
According to the CDC report, which covered a period from Nov. 30, 2020, to March 20, Test to Play was implemented at 127 public high schools in Utah and helped them complete 95% of scheduled winter sports competitions. Test to Stay saved an estimated 109,752 days of in-person learning at 13 schools, the report found. The report did not assess the impact of the testing programs or other interventions, such as masking, on COVID-19 transmission in schools, though noted that by identifying 1,886 cases among students, "Utah's testing programs likely helped reduce SARS-CoV-2 transmission in schools and communities through isolation of students with diagnosed infections and quarantine of contacts."
"School-based COVID-19 testing should be considered as part of a comprehensive prevention strategy to help identify SARS-CoV-2 infections in schools and sustain in-person instruction and extracurricular activities," the report stated, noting that Utah's approach "could serve as a framework" for other areas.
COVID-19 testing is one of several mitigation measures, including mask-wearing and physical distancing, that Utah schools have utilized. But as more students fully return to the classroom, physical distancing may be harder to enforce. Masks also continue to be a contentious issue; the CDC currently recommends consistent and correct mask use for adults and children in schools, regardless of vaccination status, though several states, including Texas, Iowa and Utah, have passed orders or bills banning public schools from requiring them.
"That worries me a lot, if you have a large percentage of unvaccinated students, plus now you're getting rid of a mitigation measure," Dr. Sara Bode, a member of the American Academy of Pediatrics' Council on School Health, told ABC News.
A testing strategy would be "another mitigation layer" to help reduce the risk of exposure, she said.
Some school districts, like New York City, have been conducting randomized surveillance testing, which officials said will continue this fall when a remote learning option will be eliminated; others, like Newark, New Jersey, are conducting weekly pooled testing. OPS PROTECTS, an Omaha Public School district pilot program conducted in a partnership with the University of Nebraska Medical Center this school year, proactively screened students and staff without COVID-19 symptoms weekly using saliva testing.
"There's multiple ways to approach school-based testing," Dr. Jana Broadhurst, director of UNMC's emerging pathogens laboratory and biocontainment unit clinical laboratory, told ABC News. "Communities would have to some degree their own unique experience."
Though COVID-19 tests are easier to obtain than they were at the start of this school year -- in March, the Biden administration also announced it would allocate $10 billion toward implementing COVID-19 screening tests for teachers, staff and students -- testing strategies, from which test is employed to how frequently its administered, may vary depending on a school district's resources. The CDC currently recommends weekly testing of teachers and school staff and testing of students at certain levels of community spread, since testing all students may not be feasible.
Implementing Utah's testing strategies was a "huge lift" for schools and local health departments, Babitz said. Ideally, testing students participating in extracurriculars at least once a week -- instead of every 14 days, as implemented -- would have been optimal, but "there was not the capacity to do it more frequently" in schools, she said. "This was a compromise."
Another compromise was the outbreak threshold for Test to Stay. When the program officially launched in January, the threshold to implement school-wide testing was 15 school-associated cases in the previous 14 days for schools with fewer than 1,500 students and staff, or 1% of the school population for those with more. Since then, the state has raised it to 30 cases, or 2% of the population, Babitz said.
"We started seeing a lot of testing burnout and fatigue with our school partners," she said. "From a public health perspective, we want to see that threshold lower, and so we're trying to build up our capacity to do that testing for them, and they're hoping to do that testing less frequently."
The health department now has an option for schools to reach out directly to its mobile test teams and request testing for any of their events, Babitz said.
The Test to Play strategy primarily targeted high schools, where spread was initially greater. Though as COVID-19 outbreaks and school-wide testing have become more frequent among middle school students and younger -- populations that aren't yet fully vaccinated -- Babitz said they're looking to implement a similar extracurricular activity testing approach for those younger age groups.
How to test?
The Utah health department has been using rapid antigen test kits, which allows schools to get results in 15 minutes and therefore quickly isolate positive cases. Though Babitz said it is now looking to do more frequent PCR tests to monitor the spread of variants.
OPS PROTECTS used a saliva PCR test specifically so it could monitor variant strains.
"It was important to us that we were collecting samples in a way that would be amenable to viral sequencing and monitoring the emergence of variants," Broadhurst said. "There's going to be a need to evaluate either on an individual or community level, how our immunity to circulating variants is holding up."
UMNC is looking to develop laboratory tools that can help them monitor immunity to variant strains over the coming year, she said.
"I think that will be an important added dimension of the testing strategy," said Broadhurst.
Even as more people, including those under 16, get vaccinated, COVID-19 testing across the board is going to be "really important" this fall, Bode said.
As schools prepare for the fall, other mitigation measures like ventilation and masking will continue to be key, health experts say. A recent analysis from the CDC and the Georgia health department found that improving ventilation, along with requiring masks among teachers and staff, helped reduce COVID-19 cases in Georgia elementary schools.
Schools may also need to anticipate other outbreaks. After low flu levels this season, experts anticipate the next one may be a "bad year for flu," Broadhurst said. Some tests are being developed that test for both COVID-19 and influenza A and B, though it's unclear how schools may act on that information, she said.
"That's going to be a complicating factor for individual and community experience coming into the fall," she said. "That I think is a question that is still being grappled with."