Speaker
Description
Understanding the role of schools in SARS-CoV-2 transmission is essential for designing effective public health policies. We developed a stochastic age-stratified transmission model, fitted to epidemiological and contact survey data, to evaluate how alternative school closure and reopening strategies could have shaped the COVID-19 pandemic in the Netherlands from early 2020 to late 2021. Using counterfactual simulations, we quantified the impact of elementary and secondary school interventions on infections and hospitalizations. We also applied time-varying elasticity analysis to quantify how age groups and school levels contributed to transmission over time.
School closures reduced transmission and healthcare burden, but their effectiveness was strongly context-dependent and varied across pandemic phases. The relative contribution of age groups to transmission also changed over time: adults dominated early in the pandemic, adolescents played a larger role during late 2020 and early 2021, while children became increasingly important in late 2021. Consequently, secondary schools had a larger impact on hospitalizations during earlier phases, whereas elementary schools became more influential later, partly due to lower infection- and vaccine-induced immunity among younger children. These findings highlight the importance of accounting for age-specific transmission dynamics when evaluating school policies and support more targeted and adaptive strategies during future pandemics.
