High vaccine effectiveness against severe COVID-19 outcomes and population preventable fraction during the Omicron era in Luxembourg:A nationwide retrospective risk factor analysis

Background: Luxembourg experienced major consecutive SARS-CoV-2 infection waves due to Omicron variants during 2022 while having achieved a high vaccination coverage in 2021. We investigated the risk factors associated to severe outcomes (i.e., hospitalisation, deaths) and estimated vaccine effectiveness (VE) as well as the role of immunity conferred by prior infections against severe outcomes in adults. Methods: We linked reported SARS-CoV-2 cases among residents aged = 20 years with vaccination data and SARS-CoV-2 related hospitalisations and deaths. Cases were followed-up until day 14 for C... Mehr ...