Modifications to student quarantine policies in K–12 schools implementing multiple COVID-19 prevention strategies restores in-person education without increasing SARS-CoV-2 transmission risk, January-March 2021

Objective To determine whether modified K–12 student quarantine policies that allow some students to continue in-person education during their quarantine period increase schoolwide SARS-CoV-2 transmission risk following the increase in cases in winter 2020-2021. Methods We conducted a prospective cohort study of COVID-19 cases and exposures among students and staff (n=65,621) in 103 Missouri public schools. Participants were offered free, saliva-based RT-PCR testing. An adjusted Cox regression model compared hazard rates of school-based SARS-CoV-2 infections between schools with a modified versus standard quarantine policy. Results From January–March 2021, a projected 23 (1%) school-based transmission events occurred among 1,636 school close contacts. There was no difference in the adjusted hazard rates of school-based SARS-CoV-2 infections between schools with a modified versus standard quarantine policy (hazard ratio=1.00; 95% confidence interval: 0.97–1.03). Discussion School-based SARS-CoV-2 transmission was rare in 103 K–12 schools implementing multiple COVID-19 prevention strategies. Modified student quarantine policies were not associated with increased school incidence of COVID-19. Modifications to student quarantine policies may be a useful strategy for K–12 schools to safely reduce disruptions to in-person education during times of increased COVID-19 community incidence.