Examining SARS-CoV-2 Interventions in Residential Colleges Using an Empirical Network

Hambridge, Hali L.; Kahn, Rebecca; Onnela, Jukka-Pekka

ObjectivesUniversities have turned to SARS-CoV-2 models to examine campus reopening strategies. While these studies have explored a variety of modeling techniques, none have used empirical data. MethodsHere, we use an empirical proximity network of college freshmen, ascertained using smartphone Bluetooth, to simulate the spread of the virus. We investigate the role of immunization, testing, isolation, mask wearing, and social distancing in the presence of implementation challenges and imperfect compliance. ResultsWe show that while frequent testing can drastically reduce spread if immunity levels are low, its effects are limited if immunity is more ubiquitous. Furthermore, while moderate levels of mask wearing and social distancing can offer additional reductions in cumulative incidence, their benefit declines rapidly as immunity and testing frequency increase. However, if immunity from vaccination is imperfect or declines over time, scenarios not studied here, frequent testing and other interventions may play a more central role. ConclusionsOur findings suggest that while regular testing and isolation are powerful tools, they have limited benefit if immunity is high or other interventions are widely adopted. If universities can attain even moderate levels of vaccination, masking, and social distancing, they may be able to relax testing frequency to once every four weeks.