The King's College London Coronavirus Health and Experiences of Colleagues at King's Study: SARS-CoV-2 antibody response in a higher education sample

Leightley, D.; Vitiello, V.; Wickersham, A.; Davis, K. A. S.; Bergin-Cartwright, G.; Lavelle, G.; Stevelink, S. A. M.; Hotopf, M.; Razavi, R.

Objective: To assess the feasibility of home antibody testing as part of large-scale study, the King's College London Coronavirus Health and Experiences of Colleagues at King's (KCL CHECK). Methods: Participants of the KCL CHECK study were sent a SureScreen Diagnostics COVID-19 IgG/IgM Rapid Test Cassette to complete at home in June 2020 (phase 1) and September 2020 (phase 2). Participants were asked to upload a test result image to a study website. Test result images and sociodemographic information were analysed by the research team. Results: A total of n=2716 participants enrolled in the KCL CHECK study, with n=2003 (73.7%) and n=1825 (69.3%) consenting and responding to phase 1 and 2. Of these, n=1882 (93.9%; phase 1) and n=1675 (91.8%; phase 2) returned a valid result. n=123 (6.5%; phase 1) and n=91 (5.4%; phase 2) tested positive for SARS-CoV-2 antibodies. A total of n=1488 participants provided a result in both phases, with n=57 (3.8%) testing positive for SARS-CoV-2 antibodies across both phases, suggesting a reduction in the number of positive antibody results over time. Initial comparisons showed variation by age group, gender and clinical role. Conclusions: Our study highlights the feasibility of rapid, repeated and low-cost SARS-CoV-2 serological testing without the need for face-to-face contact.