Vaccine effectiveness against influenza A in older adults and the effect of chronic conditions : results from the I-MOVE and VEBIS multicentre European hospital case–control studies, 2015/16–2023/24
Background: The Influenza – Monitoring Vaccine Effectiveness in Europe (I-MOVE/I-MOVE+) and Vaccine Effectiveness, Burden and Impact Studies (VEBIS) hospital networks have conducted seasonal multicentre, test-negative, case–control studies in Europe to measure influenza vaccine effectiveness (IVE) since 2015/16. We measured the effect of chronic conditions on VE of influenza A subtypes among older
