Alternative Covid-19 mitigation measures in school classrooms: Analysis using an agent-based model of SARS-CoV-2 transmission

The SARS-CoV-2 epidemic continues to have major impacts on children’s
education, with schools required to implement infection control measures
that have led to long periods of absence and classroom closures. We have
developed an agent-based epidemiological model of SARS-CoV-2 transmission
that allows us to quantify projected infection patterns within primary
school classrooms, and related uncertainties; the basis of our approach is
a contact model constructed using random networks, informed by structured
expert judgment. The effectiveness of mitigation strategies is considered
in terms of effectiveness at suppressing infection outbreaks and limiting
pupil absence. Covid-19 infections in schools in the UK in Autumn 2020 are
re-examined and the model used for forecasting infection levels in autumn
2021, as the more infectious Delta-variant was emerging and school
transmission was thought likely to play a major role in an incipient new
wave of the epidemic. Our results are in good agreement with available
data and indicate that testing-based surveillance of infections in the
classroom population with isolation of positive cases is a more effective
mitigation measure than bubble quarantine both for reducing transmission
in primary schools and for avoiding pupil absence, even accounting for the
insensitivity of self-administered tests. Bubble quarantine entails large
numbers of pupils being absent from school, with only a modest impact on
classroom infection levels. However, maintaining a reduced contact rate
within the classroom can have a major beneficial impact on managing
Covid-19 in school settings.