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

Objective: This study aims at investigating associations between COVID-19 mortality and SARS-COV-2 variants spread during the second wave of COVID-19 pandemic in Europe.

Methods: For 38 European countries, data on numbers of COVID-19 deaths, SARS-COV-2 variants spread through time using Nextstrain classification, demographic and health characteristics were collected. Cumulative number of COVID-19 deaths and 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.

Results: The average proportion of B.1.1.7 variant was found to be a significant predictor of cumulative COVID-19 deaths within two months before the peak and between 1 January-25 February 2021, as well as of the deaths peak height considering proportions during the second wave and the pre-peak period. The average proportion of EU2 variant (S:477 N) was a significant predictor of cumulative COVID-19 deaths in the pre-peak period.

Conclusions: Our findings suggest that spread of a new variant of concern B.1.1.7 had a significant impact on mortality during the second wave of COVID-19 pandemic in Europe and that proportions of EU2 and B.1.1.7 variants were associated with increased mortality in the initial phase of that wave.