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
(2025) In BMC Medicine 23. p.1-14- Abstract
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 adults (≥ 65 years) using pooled-season data (2015/16–2023/24). Methods: Hospital teams swabbed patients with severe acute respiratory infection (SARI) within 7 days of symptom onset. Cases were RT-PCR positive for influenza A(H1N1)pdm09 or A(H3N2); controls negative for any influenza virus. We calculated overall pooled-season IVE against... (More)
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 adults (≥ 65 years) using pooled-season data (2015/16–2023/24). Methods: Hospital teams swabbed patients with severe acute respiratory infection (SARI) within 7 days of symptom onset. Cases were RT-PCR positive for influenza A(H1N1)pdm09 or A(H3N2); controls negative for any influenza virus. We calculated overall pooled-season IVE against influenza A(H1N1)pdm09 and A(H3N2), adjusted for study site, sex, age and onset date; and stratified by number of and by each chronic condition (diabetes, heart disease, lung disease/asthma, immunosuppression, kidney disease, liver disease, cancer, obesity). We investigated interaction between vaccination and each condition. Results: We included 1805 A(H1N1)pdm09 cases with 16,329 controls; 2590 A(H3N2) cases with 14,920 controls, from 13 study sites (12 countries). Over all seasons, 63–67% cases and 70% controls had ≥ 2 chronic conditions. Against A(H1N1)pdm09, pooled-season IVE was 37% (95%CI: 29–44) overall; 49% (95%CI: 9–72), 30% (95%CI: 12–44) and 38% (95%CI: 29–46) in those with 0, 1, ≥ 2 chronic conditions. Most IVE point estimates were 34–45%, apart from immunosuppression (-7%), kidney disease (17%) and liver disease (54%), but 95% CIs overlapped. Significant interaction was observed for kidney disease (p = 0.02) and immunosuppression (p = 0.01). Against A(H3N2), pooled-season IVE was 17% (95%CI: 8–25) overall; 15% (95%CI: -26–42), 11% (95%CI: -8–27) and 18% (95%CI: 7–28) in those with 0, 1, ≥ 2 chronic conditions. Here, IVE point estimates ranged 13–25%, apart from immunosuppression (5%), kidney disease (6%) and liver disease (31%), although 95% CIs overlapped. There were no significant interactions. Conclusions: Pooled-season results suggest low–moderate VE against influenza A subtypes among older SARI patients; higher against A(H1N1)pdm09 than A(H3N2), with little evidence of chronic condition modifying effect, apart from kidney disease and immunosuppression. We stress the importance of developing improved influenza vaccines for specific populations, and encourage further research into the effect of chronic conditions on IVE in older adults.
(Less)
- author
- contributor
- Gefenaite, Giedre
LU
- author collaboration
- organization
- publishing date
- 2025-12
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Chronic conditions, Europe, Hospital, Influenza, Vaccine effectiveness
- in
- BMC Medicine
- volume
- 23
- article number
- 602
- pages
- 1 - 14
- publisher
- BioMed Central (BMC)
- external identifiers
-
- scopus:105020774916
- pmid:41185010
- ISSN
- 1741-7015
- DOI
- 10.1186/s12916-025-04426-y
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © The Author(s) 2025.
- id
- b22330de-4c55-4b79-8960-af449b2012f8
- date added to LUP
- 2025-12-08 11:36:41
- date last changed
- 2025-12-10 03:27:09
@article{b22330de-4c55-4b79-8960-af449b2012f8,
abstract = {{<p>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 adults (≥ 65 years) using pooled-season data (2015/16–2023/24). Methods: Hospital teams swabbed patients with severe acute respiratory infection (SARI) within 7 days of symptom onset. Cases were RT-PCR positive for influenza A(H1N1)pdm09 or A(H3N2); controls negative for any influenza virus. We calculated overall pooled-season IVE against influenza A(H1N1)pdm09 and A(H3N2), adjusted for study site, sex, age and onset date; and stratified by number of and by each chronic condition (diabetes, heart disease, lung disease/asthma, immunosuppression, kidney disease, liver disease, cancer, obesity). We investigated interaction between vaccination and each condition. Results: We included 1805 A(H1N1)pdm09 cases with 16,329 controls; 2590 A(H3N2) cases with 14,920 controls, from 13 study sites (12 countries). Over all seasons, 63–67% cases and 70% controls had ≥ 2 chronic conditions. Against A(H1N1)pdm09, pooled-season IVE was 37% (95%CI: 29–44) overall; 49% (95%CI: 9–72), 30% (95%CI: 12–44) and 38% (95%CI: 29–46) in those with 0, 1, ≥ 2 chronic conditions. Most IVE point estimates were 34–45%, apart from immunosuppression (-7%), kidney disease (17%) and liver disease (54%), but 95% CIs overlapped. Significant interaction was observed for kidney disease (p = 0.02) and immunosuppression (p = 0.01). Against A(H3N2), pooled-season IVE was 17% (95%CI: 8–25) overall; 15% (95%CI: -26–42), 11% (95%CI: -8–27) and 18% (95%CI: 7–28) in those with 0, 1, ≥ 2 chronic conditions. Here, IVE point estimates ranged 13–25%, apart from immunosuppression (5%), kidney disease (6%) and liver disease (31%), although 95% CIs overlapped. There were no significant interactions. Conclusions: Pooled-season results suggest low–moderate VE against influenza A subtypes among older SARI patients; higher against A(H1N1)pdm09 than A(H3N2), with little evidence of chronic condition modifying effect, apart from kidney disease and immunosuppression. We stress the importance of developing improved influenza vaccines for specific populations, and encourage further research into the effect of chronic conditions on IVE in older adults.</p>}},
author = {{Rose, Angela Mary Catherine and Nicolay, Nathalie and Mazagatos, Clara and Martínez-Baz, Iván and Launay, Odile and De Mot, Laurane and Bella, Antonino and Lazar, Mihaela and Machado, Ausenda and Kuliešė, Monika and Abela, Stephen and Vučina, Vesna Višekruna and van Gageldonk-Lafeber, Rianne and Bino, Silvia and Dürrwald, Ralf and Paradowska-Stankiewicz, Iwona and Horváth, Judit Krisztina and Duffy, Róisín and Husa, Petr and McMenamin, Jim and Pozo, Francisco and Howard, Jennifer and Latorre-Millán, Miriam and Castilla, Jesús and Nguyen, Liem Binh Luong and Dauby, Nicolas and Riccardo, Flavia and Ivanciuc, Alina and Gomez, Verónica and Jančorienė, Ligita and Xuereb, Gerd and Petrović, Goranka and Marbus, Sierk and Vasili, Adela and Tolksdorf, Kristin and Bogusz, Joanna and Oroszi, Beatrix and Domegan, Lisa and Součková, Lenka and Marsh, Kimberley and Bacci, Sabrina and Kissling, Esther}},
issn = {{1741-7015}},
keywords = {{Chronic conditions; Europe; Hospital; Influenza; Vaccine effectiveness}},
language = {{eng}},
pages = {{1--14}},
publisher = {{BioMed Central (BMC)}},
series = {{BMC Medicine}},
title = {{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}},
url = {{http://dx.doi.org/10.1186/s12916-025-04426-y}},
doi = {{10.1186/s12916-025-04426-y}},
volume = {{23}},
year = {{2025}},
}