Individual-based modeling of day care centers can predict optimal surveillance strategies against SARS-CoV-2

During the recent SARS-CoV-2 pandemic, governments worldwide have implementedseveral interventions to prevent the viral spread. Besides mandatory mask-wearing andrestrictions on gathering events these also included the closure of day care centers forchildren. This globally implemented strategy resulted in negative effects on children’s healthand well-being. Therefore, we aim to identify optimal surveillance strategies that preventthe closure of day care centers while minimizing the internal viral spread. In previous studies, we developed an individual-based SIR-type model that simulates theinfection spread in a day care center [1,2]. We could show that for the alpha variant thisinfection spread is governed by various testing regimes and infection surveillance policiessuch as test frequency and quarantine policy. In the current study, we extend the model for various other variants and test types and alsoaccount for vaccination of individuals. Furthermore, in the model infection spread issimulated by a susceptible individual becoming infected with a specific infection rate. Thisinfection rate is based on the current viral load of already infected individuals. Therefore,for each individual a temporal viral load kinetic is simulated, which was previously doneusing a piecewise linear model. In the current study we propose an alternative model togenerate individual viral load kinetics based on a mechanistic model of ordinary differentialequations that consider the interplay between viral particles and the immune system in thehuman lung. To adequately adapt our extended SIR model to the specific infection dynamicsof Sars-CoV-2 measured over the past years, all unknown parameters of our underlying ODEmodel are fitted to experimental data. In conclusion, our model is able to predict optimal surveillance strategies required to keepchild care centers open in various pandemic situations. [1] Engels, G. et al. (2022). “Acceptance of Different Self-sampling Methods for SemiweeklySARS-CoV-2 Testing in Asymptomatic Children and Childcare Workers at German Day CareCenters: A Nonrandomized Controlled Trial”. In: JAMA Network Open 5.9, e2231798–e2231798.[2] Forster, J. et al. (2022). “Feasibility of SARS-CoV-2 surveillance testing among childrenand childcare workers at German day care centers: a nonrandomized controlled trial”. In:JAMA Network Open 5.1, e2142057–e2142057.