Children with backpacks running at school

Landmark study of COVID-19 infection among K-12 students debunks early fears about transmission at schools

Debunking a fear that was widespread at the beginning of the COVID-19 pandemic, a novel CHOC- and UC Irvine-led study of SARS-CoV-2 infection rates among the K-12 population concludes that within-school transmission of the virus is limited.

The “Healthy School Restart Study,” one of the first to provide essential research on COVID-19 transmission in children and adolescents as schools started reopening last fall, also concludes that although the compliance rate to such mitigation guidelines as wearing face coverings and practicing social distancing at the four Orange County schools directly observed by investigators varied, it averaged about 90 percent.

The seminal research paper is under review and is expected to be published soon, says Dr. Dan Cooper, who treats kids with lung conditions at CHOC and who serves as director of UC Irvine’s Institute for Clinical & Translational Science. Dr. Cooper is a multiple principal investigator of the study along with Dr. Erlinda Ulloa, a CHOC infectious disease specialist and an assistant professor in the Department of Pediatrics at the UCI School of Medicine.

Dr. Dan Cooper, pediatric pulmonologist at CHOC

“The number one fear was that, just like influenza, children would be a reservoir for COVID-19 and would spread it to each other at schools and then spread it to adults,” Dr. Cooper says. “The data is showing us, fortunately, that that’s not the case. While such spread can occur, it is limited and when schools follow standard mitigation procedures, spread is minimal.”

The study, a joint effort of CHOC, UCI Health and the Orange County Health Care Agency, found that infection rates at schools reflected those of the community, and that neither remote learning nor highly mitigated onsite school attendance could eliminate SARS-CoV-2 infection.

“It would be disingenuous to say it’s 100-percent safe to return to schools – we’re still in a pandemic,” Dr. Cooper says. “It would be wrong to say there’s absolutely no risk in sending your child back to school, but it would also be wrong to say there’s no risk in not sending your child back to school.”

A total of320 students ages 7 to 17, as well as 99 school staff members, participated in the research project by agreeing to nasal swab and blood testing. Two of the schools in the study serve low-income Hispanic learners. One school serves a high proportion of kids with special needs, and the fourth school serves predominately white kids from upper- and middle-class families. The first three schools mainly provided remote instruction, while the fourth school predominantly provided onsite instruction.

“The four participating schools reflected the enormous diversity of income, community COVID-19 case rates, school type (private, charter, public), and learning status (remote vs. onsite) that face learners, school staff, and policy makers across the United States,” the paper states.

The study was done in two phases – in early fall, when there were lower levels of COVID-19 cases, and a second time during the late fall-winter surge, when there was a tenfold increase in COVID-19 cases. Trained observers studied kids four times a day – during classroom learning, at active recess, during PE, and during communal lunch.

During the first testing phase, no kids tested positive for COVID-19. During the second phase, 17 kids tested positive for the virus, along with six staff members.

School A, which primarily serves lower-income Hispanic students and had 97 percent of its students engaged in remote learning, had the highest infection rate, at 12.9 percent. School D, which serves upper- and middle-class students who primarily attended class in person, had the lowest infection rate, at 1.2 percent.

In the aggregate, there was no statistically significant difference in SARS-CoV-2 positive rates among remote or onsite learners, the study found.

In addition, the study found there was a significant relationship between SARS-CoV-2 positivity and presence of symptoms – data that supports the use of limited symptom screening as a mechanism to enhance healthy school reopening.

Investigators also tested for 21 other circulating respiratory pathogens and turned up no signs of the influenza virus – just the common-cold rhinovirus, which stays functional on surfaces such as desktops for much longer intervals than the coronavirus or influenza virus.

“The mitigation procedures and cleanliness procedures that had been put in place got rid of the flu,” Dr. Cooper notes.

He adds: “This study should make parents feel better and prompt them to ask the right questions to their school. Parents should ask, ‘What are your mitigation plans? How are you making sure people are paying attention to your plan? What happens to a child who reports symptoms during the day? Do you have a plan?’ That’s what I would want to know as a parent.”

Mitigation procedures should remain

With widespread implementation of pediatric COVID-19 vaccination still many months away, it’s likely that adherence to COVID-19 mitigation procedures, including physical distancing and face covering, will need to continue for the near future, the study concluded.

Dr. Cooper notes that some students, mostly from lower-income families, are going on a year without in-classroom learning – an unfortunate situation that comes with many disadvantages, such as more sedentary time at home on the computer and increased obesity and depression.

“We have to weigh the damage to kids of keeping schools closed,” he says. “Who is being impacted most? It’s the low-income kids.”

In addition to Dr. Cooper and Dr. Ulloa, other CHOC and UCI personnel who participated in the “Healthy School Restart Study” included Jessica Ardo, Kirsten Casper, Andria Meyer, and Diana Stephens, clinical research coordinators; Dr. Charles Golden, vice president and executive medical director of the CHOC Primary Care Network; and Dr. Michael Weiss, vice president of population health at CHOC.

The authors of the research paper also acknowledged the “outstanding management” of the complex study by Phuong Dao, director of research operations; Brent Dethlefs, executive director of research; and other staff members of the CHOC Research Institute.

In another research paper, published in late February 2021 in the journal Pediatric Research, Dr. Cooper and Dr. Ulloa addressed the biologic, ethical, research and implementation challenges of SARS-CoV-2 vaccine testing and trials in the pediatric population.

Among others, the paper was co-authored by Dr. Coleen Cunningham, CHOC’s new senior vice president and pediatrician-in-chief, as well as chair of the UCI Department of Pediatrics, and Dr. Jasjit Singh, a CHOC infectious disease specialist.

Children under the age of 12, this paper notes, have yet to be enrolled in COVID-19 vaccine trials.

The paper states that enrolling children in medical research involves a balance between access to experimental but potentially life-saving therapeutics and protection from unsafe or ineffective therapeutics.

The paper notes that in the early stages of the pandemic, a national working group convened and published a commentary outlining the challenges ahead that would inevitably need to be addressed as schools reopened. That commentary, the paper says, included a message that resonates with the immediate challenge of pediatric SARS-CoV-2 vaccine testing and clinical trials:

“This could be accomplished by building public health-focused collaboratives capable of continuous learning and rapid cycles of implementation, as COVID-19 information evolves at breakneck speed. Otherwise, we risk further compounding the incalculable damage already incurred by COVID-19 among children across our country and the world.”

Read more about the Healthy School Restart Study.

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