The COVID-19 Schools Infection Survey in England: Protocol and Participation Profile for a Prospective Observational Cohort Study

Abstract

Background One of the most debated questions in the COVID-19 pandemic has been the role of schools in SARS-CoV-2 transmission. The COVID-19 Schools Infection Survey (SIS) aims to provide much-needed evidence addressing this issue. Objective We present the study protocol and participation profile for the SIS study, aimed at assessing the role of schools in SARS-CoV-2 infection and transmission within school settings, and investigating how transmission within and from schools could be mitigated through the implementation of school COVID-19 control measures. Methods SIS was a multisite, prospective, observational cohort study conducted in a stratified random sample of primary and secondary schools in selected local authorities in England. A total of 6 biobehavioral surveys were planned among participating students and staff during the 2020-2021 academic year, between November 2020 and July 2021. Key measurements were SARS-CoV-2 virus prevalence, assessed by nasal swab polymerase chain reaction; anti-SARS-CoV-2 (nucleocapsid protein) antibody prevalence and conversion, assessed in finger-prick blood for staff and oral fluid for students; student and staff school attendance rates; feasibility and acceptability of school-level implementation of SARS-CoV-2 control measures; and investigation of selected school outbreaks. The study was approved by the United Kingdom Health Security Agency Research Support and Governance Office (NR0237) and London School of Hygiene & Tropical Medicine Ethics Review Committee (reference 22657). Results Data collection and laboratory analyses were completed by September 2021. A total of 22,585 individuals—1891 staff and 4654 students from 59 primary schools and 5852 staff and 10,188 students from 97 secondary schools—participated in at least one survey. Across all survey rounds, staff and student participation rates were 45.2% and 16.4%, respectively, in primary schools and 30% and 15.2%, respectively, in secondary schools. Although primary student participation increased over time, and secondary student participation remained reasonably consistent, staff participation declined across rounds, especially for secondary school staff (3165/7583, 41.7% in round 1 and 2290/10,374, 22.1% in round 6). Although staff participation overall was generally reflective of the eligible staff population, student participation was higher in schools with low absenteeism, a lower proportion of students eligible for free school meals, and from schools in the least deprived locations (in primary schools, 446/4654, 9.6% of participating students were from schools in the least deprived quintile compared with 1262/22,225, 5.7% of eligible students). Conclusions We outline the study design, methods, and participation, and reflect on the strengths of the SIS study as well as the practical challenges encountered and the strategies implemented to address these challenges. The SIS study, by measuring current and incident infection over time, alongside the implementation of control measures in schools across a range of settings in England, aims to inform national guidance and public health policy for educational settings. International Registered Report Identifier (IRRID) RR1-10.2196/34075

Epidemiology of SARS-CoV-2 infection among staff and students in a cohort of English primary and secondary schools during 2020–2021

“…SIS testing rounds are shown, as well as school closures and national community “lockdowns” in response to the pandemic. 12 Although the initial high prevalence LAs had the highest prevalence in Autumn 2020, this pattern changed with the Alpha variant in early 2021. Schools were closed to most students from 06 January to 08 March 2021 and remained open when the Delta variant emerged in England from April 2021.…”

“…SIS was a longitudinal, population-based observational study in a cohort of students and staff from selected schools in 15 local authorities (LAs) across England with stratified sampling based on case rates in September 2020. 12 The study was designed to run through the school year 2020–2021 with open enrolment and plans for six rounds (two per term) of school- and home-based (from round 2) sample collection.…”

“…The sampling design and data-collection methods of the study have been described previously. 12 Briefly, during the autumn term of the school year 2020–2021, we set out to recruit approximately 50 primary and 100 secondary schools from 15 LAs in England to participate in a year-long cohort study. To facilitate transmission studies, we selected LAs to over-represent locations with a high burden of community COVID-19 cases at the start of the 2020–2021 school year.…”

“…There was a rolling recruitment process for schools and participants (people who provided at least one sample) within those schools from October 2020 to May 2021, although not all schools participated in all the rounds. 12 All students from 4 years of age and all staff in primary schools were eligible to join the study from the start (November 2020). For secondary students, in the first term (November-December 2020), only those from two systematically selected consecutive year-groups were eligible in any one school: years 7 and 8 (ages 11–13); 9 and 10 (ages 13–15); or years 12 and 13 (ages 16–18) were randomly selected to participate in each school.…”

“…The sample size and design for the study were limited by pragmatic and logistical considerations as described previously. 12 …”