On the association between SARS-COV-2 variants and COVID-19 mortality during the second wave of the pandemic in Europe

Abstract

AbstractBACKGROUNDPreliminary clinical evidence suggests an increased COVID-19 mortality associated with the variant of concern 20I/501Y.V1. The evidence outside the UK and a real-world comparison of variants spread and mortality is sparse. This study aims at investigating the association between COVID-19 mortality and SARS-COV-2 variants spread during the second wave of the COVID-19 pandemic in Europe.METHODSFor 38 European countries, publicly available data were collected on numbers of COVID-19 deaths, SARS-COV-2 variants spread through time using Nextstrain classification and countries’ demographic and health characteristics. The cumulative number of COVID-19 deaths and the height of COVID-19 daily deaths peak during the second wave of the pandemic were considered as outcomes. Pearson correlations and multivariate generalized linear models with selection algorithms were used.FINDINGSThe average proportion of 20I/501Y.V1 variant (B.1.1.7) was found to be a significant predictor of cumulative number of COVID-19 deaths within two months before the deaths peak and between 1 January – 25 February 2021, as well as of the deaths’ peak height when calculating the proportion during the second wave and the pre-peak period. The average proportion of 20A.EU2 variant (S:477N) was a significant predictor of cumulative COVID-19 deaths in the pre-peak period.INTERPRETATIONOur findings suggest that the spread of a new variant of concern 20I/501Y.V1 had a significant impact on the mortality during the second wave of COVID-19 pandemic in Europe and that proportions of 20A.EU2 and 20I/501Y.V1 variants were associated with increased mortality in the initial phase of that wave.Research in contextEvidence before this studyEmerging evidence suggests that the new variant of concern 20I/501Y.V1 (B.1.1.7) may be associated with an increased risk of death. The 20A.EU2 variant (S:447N), observed firstly in July 2020 in western Europe, was found to be capable of increasing SARS-COV-2 infectivity. The evidence outside the UK is still sparse, same as a real-world comparison of distinct variants spread and mortality through time.Added value of this studyIn this study we investigated whether the change of the proportion of any SARS-COV-2 variant, including 20I/501Y.V1 and 11 other variants identified by Nextstrain up to 25 February 2021, has an association with COVID-19 cumulative mortality or with the height of the second wave COVID-19 mortality peak.Implications of all the available evidenceOur findings shed light on the causes of the increased COVID-19 mortality during the second wave of the pandemic in Europe. It shows the need for early containment strategies when the variant 20I/501Y.V1 emerges. These findings also support the need for systematic SARS-CoV-2 regular genome sequencing to control the COVID-19 pandemic.