Interim analysis of COVID-19 vaccine effectiveness against hospitalisation and death using electronic health records in six European countries : April 2022 to March 2023

This report presents pooled COVID-19 vaccine effectiveness (VE) estimates for the first, second and third booster doses, against hospitalisation due to COVID-19 and COVID-19 related deaths in resident populations ≥50 years of age, living in the community, in six European countries: Belgium, Denmark, Luxembourg, Navarre (Spain), Norway, and Portugal. This study was undertaken within the Vaccine Effectiveness Burden and Impact Studies (VEBIS) project. A retrospective cohort was constructed from linked electronic health records (EHR) in each country. Countryspecific (level) relative VE (rVE) was estimated on a monthly basis, using a study period covering an eight-week follow-up period. Each month the study period was shifted forward to the following month. Country estimates were then pooled together. The study period covered in this report is April 2022 to March 2023. The rVE of first, second and third booster doses was estimated and compared to the VE of complete primary vaccination received at least 24 weeks ago (≥24 weeks).