Using an Agent-Based Model to Assess K-12 School Reopenings Under Different COVID-19 Spread Scenarios – United States, School Year 2020/21

Abstract

School-age children play a key role in the spread of airborne viruses like influenza due to the prolonged and close contacts they have in school settings. As a result, school closures and other non-pharmaceutical interventions were recommended as the first line of defense in response to the novel coronavirus pandemic (COVID-19). Assessing school reopening scenarios is a priority for states, administrators, parents, and children in order to balance educational disparities and negative population impacts of COVID-19. To address this challenge, we used an agent-based model that simulates communities across the United States including daycares, primary, and secondary schools to quantify the relative health outcomes of reopening schools. We explored different reopening scenarios including remote learning, in-person school, and several hybrid options that stratify the student population into cohorts (i.e., split cohort) in order to reduce exposure and disease spread. In addition, we assessed the combined impact of reduced in-person attendance in workplaces (e.g., through differing degrees of reliance on telework and/or temporary workplace closings) and school reopening scenarios to quantify the potential impact of additional transmission pathways contributing to COVID-19 spread. Scenarios where split cohorts of students return to school in non-overlapping formats resulted in significant decreases in the clinical attack rate (i.e., the percentage of symptomatic individuals), potentially by as much as 75% . These split cohort scenarios have impacts which are only modestly lesser than the most impactful 100% distance learning scenario. Split cohort scenarios can also significantly avert the number of cases--approximately 60M and 28M--depending on the scenario, at the national scale over the simulated eight-month period. We found the results of our simulations to be highly dependent on the number of workplaces assumed to be open for in-person business, as well as the initial level of COVID-19 incidence within the simulated community. Our results show that reducing the number of students attending school leads to better health outcomes, and the split cohort option enables part-time in-classroom education while substantially reducing risk. The results of this study can support decisions regarding optimal school reopening strategies that at the population level balance education and the negative health outcomes of COVID-19.

The impact of school reopening on COVID-19 dynamics in Bogotá, Colombia

“…may lead to a substantial increase in SARS-CoV-2 transmission in Bogotá, Colombia, but this effect can be mitigated by managing the school capacities and increasing control measures. Our results were consistent with other modeling studies suggesting that younger grades could have a lower impact in transmission than older grades [27,28,35].…”

“…For instance, in Chile, a stochastic mechanistic model has shown that early lockdowns were effective to reduce the impact of COVID-19 in Santiago de Chile, but they disproportionately benefited wealthier communities while penalizing vulnerable populations [2]. Within the context of school reopenings, various models suggest that the risk of reopening schools could be minimized with the use of interventions such as reduced class size, face-mask wearing, contact reduction by clustering students [27,28,29,30,31]. Importantly, these models agree that the risk of reopening is higher for older ages.…”

The efficiency of dynamic regional lockdown approach in controlling the COVID-19 epidemic. Insights from the agent-based epidemiological model for Poland

“…The results of agent-based modeling of the impact of school closings on the COVID-19 epidemic in Ontario, Canada, showed that school closings may have a limited effect in reducing the burden of the disease without other measures to disrupt the transmission chain (as community-based voluntary self-isolation) 15 . Other works also confirmed the importance of introducing other measures alongside school closure, for example, related to the reduction of contacts in the workplace 5,6 .…”

Social network-based cohorting to reduce the spread of SARS-CoV-2 in secondary schools: A simulation study in classrooms of four European countries

“…Specifically, decomposing the student population into smaller isolated units may reduce the risk of large infection clusters. While research on social distancing measures in schools is still scant, [1] emerging evidence from modelling studies for schools in the US suggests that reducing group size can indeed help reduce infections [2] , [3] , [4] , [5] , [6] , [7] , [8] , [9] . However, insights from these studies are not readily applicable to the European context characterized by different structures of in-school instruction.…”