Quantifying pupil-to-pupil SARS-CoV-2 transmission and the impact of lateral flow testing in English secondary schools

Abstract

A range of measures have been implemented to control within-school SARS-CoV-2 transmission in England, including the self-isolation of close contacts and twice weekly mass testing of secondary school pupils using lateral flow device tests (LFTs). Despite reducing transmission, isolating close contacts can lead to high levels of absences, negatively impacting pupils. To quantify pupil-to-pupil SARS-CoV-2 transmission and the impact of implemented control measures, we fit a stochastic individual-based model of secondary school infection to both swab testing data and secondary school absences data from England, and then simulate outbreaks from 31st August 2020 until 23rd May 2021. We find that the pupil-to-pupil reproduction number, Rschool, has remained below 1 on average across the study period, and that twice weekly mass testing using LFTs has helped to control pupil-to-pupil transmission. We also explore the potential benefits of alternative containment strategies, finding that a strategy of repeat testing of close contacts rather than isolation, alongside mass testing, substantially reduces absences with only a marginal increase in pupil-to-pupil transmission.

An assessment of the vaccination of school-aged children in England against SARS-CoV-2

“…The model has been extensively used throughout the pandemic, particularly to answer questions about vaccination [ 53 , 54 ] and to project the likely impact of relaxing control measures [ 55 , 56 ]. This model formulation has also been used to consider the impact of school reopening on the population level incidence [ 17 ], although bespoke individual-scale models may be more appropriate when focusing on within-school dynamics rather than their feed-back on the community [ 26 , 57 , 58 ].…”

Seasonal patterns of SARS-CoV-2 transmission in secondary schools: a modelling study

“…The baseline scenario assumes a school-related basic reproduction number for Omicron of 2.0 during the winter period (October to March) and of 1.5 during the summer period (25% decrease compared to winter, April to September), assuming a 40%-60% increase to estimates from the Delta variant. 8,10 We assumed compliance to isolation guidelines for symptomatically infected students of 33%, 26 i.e. home isolation for seven days upon a positive PCR test, but no other mitigation measures in schools.…”

“…Modelling studies in school populations thus far mainly focused on estimating within-school reproduction numbers and on short-term predictions of the potential impact of school-based mitigation measures (e.g., school closure, regular testing, maskwearing, room ventilation, cohorting) during single waves of the pandemic. [8][9][10] Regular screening using rapid antigen tests was found to be efficient in preventing infections while reducing absent student days. 8,10 Its effectiveness, however, highly depends on testing adherence and turn-around time.…”

“…[8][9][10] Regular screening using rapid antigen tests was found to be efficient in preventing infections while reducing absent student days. 8,10 Its effectiveness, however, highly depends on testing adherence and turn-around time. 8,9 A modelling study calibrated to Austrian data found that large infection clusters are effectively prevented by a combination of school-based measures only.…”

Controlling SARS-CoV-2 in schools using repetitive testing strategies

“…In fact, Engzell et al evaluated the impact of school closures on students’ learning performance, finding that students of age 8–11 years made less progress while learning from home ( Engzell et al, 2021 ). Several scientific investigation discussed the use of testing strategies in school settings, for example ( Colosi et al, 2022 ; Leng et al, 2022 ; GOV UK, 2021a ; GOV UK, 2021b ; Paltiel and Schwartz, 2021 ; Chang et al, 2020a ; Hamer et al, 2021 ), suggesting that a repetitive testing strategy reduces transmissions in a school context but increases absenteeism. In this work, we explore the effectiveness of testing strategies in a primary school setting by varying factors related to the considerate strategies and school environment, and by testing viral and immunological characteristics representing different SARS-CoV-2 VOCs.…”