Effectiveness of Influenza Vaccines and Duration of Protection Against Hospitalisation During the 2024/25 Season in Northern Ireland, UK
Influenza and Other Respiratory Viruses·
- DOI
- 10.1111/irv.70303
- PMID
- —
- PMCID
- —
- OpenAlex
- W7196951849
- Study type
- Journal article
- Publisher
- Wiley
- Article type
- journal-article
- Integrity
- current
Why this research matters now
The findings indicate that seasonal influenza vaccination provided meaningful protection against hospitalisation in 2024/25, with the largest benefit observed in children, supporting continued vaccination efforts in Northern Ireland.
Structured evidence summary
Research question
The study evaluated how well seasonal influenza vaccination prevented laboratory-confirmed influenza-associated hospitalisation during the 2024/25 season in Northern Ireland.
Study design
A test-negative design was used, linking influenza laboratory results to hospital admission and vaccination records to estimate vaccine effectiveness against hospitalisation.
Population and setting
The analysis included 15,133 hospitalised patients in Northern Ireland during the 2024/25 influenza season, of whom 2,024 (13.4%) tested positive for influenza.
Main findings
Overall vaccine effectiveness against laboratory-confirmed influenza hospitalisation was 46.0% (95% CI: 39.7%–51.8%). Effectiveness against influenza A was 41.4% across all ages, with higher estimates in children aged 2–17 years (60.8%) than in adults aged 18–64 years (40.5%) and those aged ≥65 years (42.3%). Estimates for A(H1) and A(H3) were 44.3% and 49.9%, respectively, while effectiveness against influenza B was 76.4%. For influenza A, effectiveness declined from 51.9% at 2–8 weeks post-vaccination to 41.4% at ≥16 weeks; no statistically significant differences by vaccine type were reported.
Public-health relevance
The findings indicate that seasonal influenza vaccination provided meaningful protection against hospitalisation in 2024/25, with the largest benefit observed in children, supporting continued vaccination efforts in Northern Ireland.
Important limitations
Limitations were not explicitly described in the supplied abstract. The summary is therefore restricted to the supplied single-article abstract/metadata and requires review of the original paper for decision-grade interpretation.
GIDS interpretation
The article is indexed under influenza surveillance and vaccine effectiveness topics and concerns the United Kingdom, making it discoverable to GIDS users seeking jurisdiction-specific vaccine effectiveness evidence for the 2024/25 season.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 10 auditable classifier relationships to diseases, places, topics, and study design.