The COVID-19 Schools Infection Survey in England: Protocol and participation profile for a prospective, observational cohort study (Preprint)

UNSTRUCTURED 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, and to investigate how transmission within, and from, schools could be mitigated through implementation of school COVID-19 control measures. Here we describe the study protocol and participation. SIS is a multisite, prospective, observational cohort study conducted in a stratified random sample of primary and secondary schools in selected local authorities in England. Six bio-behavioural surveys were planned among participating students and staff during the 2020/21 academic year, starting in November 2020. Key measurements are 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. During SIS, a total of 22,609 individuals: 1,902 staff and 4,674 students from 59 primary schools and 5,874 staff and 10,159 students from 97 secondary schools participated in at least one survey. Staff and student participation rates were 44.9% and 16.3% in primary schools and 30.1% and 15.0% in secondary schools. While primary student participation increased over time and secondary student participation remained reasonably consistent, staff participation declined across rounds, especially for secondary staff (41.9% in Round 1 and 21.8% in Round 6). While 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 20.5% participants were from schools in the least deprived quintile compared with 12.9% of eligible students). SIS aims to improve understanding of SARS-CoV-2 transmission and control measures in schools across a range of settings in England, serving to inform national guidance and public health policy for educational settings.