Effectiveness of vaccines in preventing hospitalization due to COVID-19: A multicenter hospital-based case-control study, Germany, June 2021 to January 2022

•This study assesses detailed first-hand data and therefore provides a very high data quality.•Detailed interviews, abstraction of medical records and laboratory analyses were combined to obtain comprehensive data sets.•More than half of the cases (58 %) were not vaccinated at all, compared to 11 % of the controls.•The vaccine effictiveness to prevent severe disease in the Delta wave was 89 % overall for two doses and 98 % for three doses.