The SARS-CoV-2 Alpha variant was associated with increased transmission relative to other variants present at the time of its emergence and several studies have shown an association between Alpha variant infection and increased hospitalisation and 28-day mortality. However, none have addressed the impact on maximum severity of illness in the general population classified by the level of respiratory support required, or death. We aimed to do this.
In this retrospective multi-centre clinical cohort sub-study of the COG-UK consortium, 1475 samples from Scottish hospitalised and community cases collected between 1st November 2020 and 30th January 2021 were sequenced. We matched sequence data to clinical outcomes as the Alpha variant became dominant in Scotland and modelled the association between Alpha variant infection and severe disease using a 4-point scale of maximum severity by 28 days: 1. no respiratory support, 2. supplemental oxygen, 3. ventilation and 4. death.
Our cumulative generalised linear mixed model analyses found evidence (cumulative odds ratio: 1.40, 95% CI: 1.02, 1.93) of a positive association between increased clinical severity and lineage (Alpha variant versus pre-Alpha variants).
The Alpha variant was associated with more severe clinical disease in the Scottish population than co-circulating lineages.
© 2023 Pascall et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. http://creativecommons.org/licenses/by/4.0/
Pascall, D., Vink, E., Blacow, R., Bulteel, N., Campbell, A., Campbell, R., Clifford, S., Davis, C., da Silva Filipe, A., El Sakka, N., Fjodorova, L., Forrest, R., Goldstein, E., Gunson, R., Haughney, J., Holden, M., Honour, P., Hughes, J., James, E., Lewis, T., Lycett, S., MacLean, O., McHugh, M., Mollett, G., Onishi, Y., Parcell, B., Ray, S., Robertson, D., Shabaan, S., Shepherd, J., Smollett, K., Templeton, K., Wastnedge, E., Wilkie, C., Williams, T., Thomson, E. & COVID-19 Genomics UK (COG-UK) consortium 2023, 'The SARS-CoV-2 Alpha variant was associated with increased clinical severity of COVID-19 in Scotland: a genomics-based retrospective cohort analysis', PLoS ONE, 18(4), article no: e0284187. https://doi.org/10.1371/journal.pone.0284187