A comparative analysis of the role of containment policies, vaccination strategies and virus variants in the COVID-19 pandemic across nine European countries

The COVID-19 pandemic disrupted public health, economies, and societies worldwide, with lasting effects still visible today. Containment policies were implemented to reduce viral transmission, but their effectiveness varied across geographic regions. Understanding the interplay between policies, epidemiological variables, vaccines, and variants is crucial for optimizing future epidemic responses. This study applies a vector autoregressive mixed-effect model to data from nine European countries over the entire pandemic duration, using weekly data to provide both global and country-specific analyses. Policy stringency was assessed using the Oxford Covid-19 Government Response Tracker. Our findings reveal that the relationship between epidemiological indicators and policy stringency evolved over time. Initially, hospitalizations were the primary driver of containment measures, but as vaccinations increased and new variants emerged, new case numbers became an important factor too. While all vaccine doses contributed to reducing cases and hospitalizations, only the second dose was associated with policy stringency. No significant association was found between virus variants and policy measures. Despite small country-specific differences, these insights highlight the complex interdependencies that shaped pandemic management. This framework can support future public health decision-making by balancing epidemiological trends with tailored policy responses at both national and international levels.