Neutralising antibodies to SARS coronavirus 2 in Scottish blood donors - a pilot study of the value of serology to determine population exposure

Craig Thompson; Nicholas Grayson; Robert Paton; José Lourenço; Bridget Penman; Lian Ni Lee; Valerie Odon; Juthathip Mongkolsapaya; Senthil Chinnakannan; Wanwisa Dejnirattisai; Matthew Edmans; Alexander Fyfe; Carol Imlach; Kreepa Kooblall; Nicholas Lim; Chang Liu; Cesar Lopez-Camacho; Carol-Anne McInally; Narayan Ramamurthy; Jeremy Ratcliff; Piyada Supasa; Beibei Wang; Alexander J Mentzer; Marc Turner; Calum Semple; John Kenneth Baillie; Heli Harvala; Gavin Screaton; Nigel Temperton; Paul Klenerman; Lisa Jarvis; Sunetra Gupta; Peter Simmonds

Compared to Italy and Spain, the SARS-CoV-2 pandemic was at a relatively early stage in 85 the UK in early March 2020. However, a dramatic rise in the number of admissions of patients with severe SARS-CoV-2 infections followed and emergency plans have been implemented. Prediction of the future severity of the outbreak, and most specifically the trajectory of severe cases that require hospitalisation and intensive care support is key to the national response, as it is throughout several affected countries worldwide. Predicting disease 90 outcomes is complex; in addition to the basic information of the proportions of individuals in different age ranges who develop severe disease, the severity of the outbreak is also crucially dependent on current population immunity and virus transmissibility. Mean estimates of R0 of 3.29 (2.12 -4.45 interquartile range from 12 studies based on presumed SARS-CoV-2 naive populations) 9 indicate that a 50%-75% minimum level of herd immunity from past 95 infection is sufficient for a sustained reduction of new infections with time. SARS-CoV-2 spread may be further influenced by seasonal changes in transmissibility, as observed for other respiratory coronaviruses infecting humans [10] [11] [12] .