Association between influenza vaccination and severe outcomes in adults aged ≥ 65 years hospitalized with laboratory-confirmed influenza: a retrospective cohort study, I-MOVE hospital network, Europe, 2015/16–2024/25
Year: 2026
Type: article
Study design: Observational Study
Abstract: INTRODUCTION: Older adults face an increased risk of influenza-related intensive care unit (ICU) admission and in-hospital death (IHD). Although vaccination reduces hospitalization, its effect on these outcomes remains uncertain. We estimated the association between influenza vaccination and both outcomes among adults aged ≥65 years hospitalized with laboratory-confirmed influenza. RESEARCH DESIGN AND METHODS: We conducted a retrospective cohort study using European I-MOVE hospital network data (2015/16-2024/25); vaccination was defined as vaccine receipt ≥14 days before symptom onset. We estimated pooled-season adjusted risk ratios (aRR) using Poisson regression adjusting for potential confounders. We calculated relative risk reduction (RRR) as (1-aRR)×100, overall and by age group (65-79, ≥80 years). RESULTS: After exclusions, 4,257 patients (five study sites, six seasons) were included. ICU admission occurred in 3% of vaccinated and 5% of unvaccinated patients; IHD occurred in 5% of both groups. RRR was 11% (95% CI: -21-34) against ICU admission (65-79 years: -4%; ≥80 years: 44%). RRR against IHD was 26% (95% CI: 3-43); 17% and 29% in each respective age group. CONCLUSIONS: Vaccination showed little or no association with ICU admission, but was associated with a one-quarter reduction in IHD among hospitalized older adults, reinforcing its benefits against fatal in-hospital outcomes.
Source: Expert Review of Vaccines
Authors: Diogo F. P. Marques, Angela M. C. Rose, Susana Monge, Iván Martínez-Baz, Marijke Reynders, Róisín Duffy, Sierk D. Marbus, Silvia Bino, Petr Husa, Ralf Dürrwald, Liem Binh Luong Nguyen, Goranka Petrović, Beatrix Oroszi, Antonino Bella, Monika Kuliese, Stephen Abela, Iwona Paradowska-Stankiewicz, Ausenda Machado, Odette Popovici, Chris Robertson, Francisco Pozo, Ana S. Lameiras Azevedo, Camino Trobajo-Sanmartín, Anna Parys, Lisa Domegan, Arianne B. van Gageldonk-Lafeber, Lenka Součková, Kristin Tolksdorf, Odile Launay, Vesna Višekruna Vučina, Gergő Túri, Flavia Riccardo, Ligita Jančorienė, John Paul Cauchi, Verónica Gómez, Mihaela Lazar, Jim McMenamin, Baltazar Nunes
Institutions: Universidade Nova de Lisboa, Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red Enfermedades Infecciosas, Instituto de Salud Pública de Navarra, Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública, AZ Sint-Jan, Health Service Executive, Health Protection Surveillance Centre, National Institute for Public Health and the Environment, Institute of Public Health, Masaryk University, University Hospital Brno, Robert Koch Institute, Inserm, Université Paris Cité, Hôpital Cochin, Assistance Publique – Hôpitaux de Paris, Centre d'Investigation Clinique de Vaccinologie Cochin-Pasteur, Hrvatski zavod za javno zdravstvo, Semmelweis University, Istituto Superiore di Sanità, Lithuanian University of Health Sciences, Narodowy Instytut Zdrowia Publicznego PZH – Państwowy Instytut Badawczy, National Institute of Health Dr. Ricardo Jorge, Institutul National de Sanatate Publica, University of Strathclyde, Public Health Scotland, Sciensano (Belgium), Vilnius University, Queen Mary University of London, University of Glasgow
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
Funders: Indian National Science Academy, European Centre for Disease Prevention and Control, University College Dublin, Lunds Universitet, Universitair Ziekenhuis Gent, Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, Lietuvos Sveikatos Mokslų Universitetas, Medicinska Fakulteten, Lunds Universitet, National Research, Development and Innovation Office, Norwegian Institute of Public Health
OpenAlex ID: W7204459350