A novel approach for evaluating contact patterns and risk mitigation strategies for COVID-19 in English primary schools with application of structured expert judgement Sparks, R. S. J. Scarrow, Jane Hannah Schools COVID-19 Expert judgement Transmission Electronic supplementary material is available online at https://doi.org/10.6084/m9.figshare.c. 5280319. The support of the Royal Society education policy unit and the RAMP initiative for COVID-19 are acknowledged. Funding to L.D. and E.B.-P. from MRC grants MR/V038613/1 and MC-PC-19067 is acknowledged. Personal contacts drive COVID-19 infections. After being closed (23 March 2020) UK primary schools partially re-opened on 1 June 2020 with social distancing and new risk mitigation strategies. We conducted a structured expert elicitation of teachers to quantify primary school contact patterns and how contact rates changed upon re-opening with risk mitigation measures in place. These rates, with uncertainties, were determined using a performance-based algorithm. We report mean number of contacts per day for four cohorts within schools, with associated 90% confidence ranges. Prior to lockdown, younger children (Reception and Year 1) made 15 contacts per day [range 8.35] within school, older children (Year 6) 18 contacts [range 5.55], teaching staff 25 contacts [range 4.55] and non-classroom staff 11 contacts [range 2.27]. After re-opening, the mean number of contacts was reduced by 53% for young children, 62% for older children, 60% for classroom staff and 64% for other staff. Contacts between teaching and non-teaching staff reduced by 80%. The distributions of contacts per person are asymmetric with heavy tail reflecting a few individuals with high contact numbers. Questions on risk mitigation and supplementary structured interviews elucidated how new measures reduced daily contacts in-school and contribute to infection risk reduction. 2021-03-04T13:29:37Z 2021-03-04T13:29:37Z 2021-01-27 info:eu-repo/semantics/article Sparks R. S. J., Aspinall W. P., Brooks-Pollock E., Cooke R. M., Danon L., Barclay J., Scarrow J. H. and Cox J. 2021A novel approach for evaluating contact patterns and risk mitigation strategies for COVID-19 in English primary schools with application of structured expert judgementR. Soc. open sci.8201566201566 [http://doi.org/10.1098/rsos.201566] http://hdl.handle.net/10481/66908 10.1098/rsos.201566 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España The Royal Society Publishing