Comparative Analysis of Mortality from Coronavirus Disease 2019 Across the European Union Countries and the Effects of Vaccine Coverage

Background: Mortality is a critical measure of disease impact. The European Union (EU) countries share the same regulatory framework but different implementation policies. Methods: We extracted cumulative COVID-19 mortality data across the EU countries. We evaluated the 27 member states using the location quotient (LQ) to adjust for the expected mortality in the whole EU region, where an LQ <1 signifies a more and an LQ >1 a less favorable outcome. We categorized EU members into 3 distinct profiles based on their LQ estimates: favorable profile, LQ ≤0.9; unfavorable profile, LQ >1.10; and average profile, LQ between 0.9 and 1.10. We compared LQ estimates and profiles with the prevaccination era that ended in December 2020 with the COVID-19 vaccine rollout. Results: Twelve member states had a favorable profile, 4 had an average profile, and 11 had an unfavorable profile. In quantitative analysis, an improvement (negative LQ difference) was noted across countries with higher vaccination coverage (median, 71% fully vaccinated vs 57% for countries with positive LQ differences). There was a significant negative association between the share of fully vaccinated and LQ changes (ρ = -0.62, P < .001) and a significant 4-month lag effect. After COVID-19 vaccines became available, 4 countries improved their profile and 5 moved to a worse profile. Conclusions: There is significant variability in mortality and impact of COVID-19 between countries, even if they share the same regulatory framework. Extending immunization coverage may lead the transition to a more favorable profile, and alter the trajectory of COVID-19 mortality.