Effectiveness of Influenza Vaccines and Duration of Protection Against Hospitalisation During the 2024/25 Season in Northern Ireland, UK

IF 3.9 4区医学 Q1 INFECTIOUS DISEASES

Influenza and Other Respiratory Viruses Pub Date : 2026-08-06 DOI:10.1111/irv.70303

Magda Bucholc, Siobhán Murphy, Mark G. O'Doherty, Suzanne Wilton, Emma Dickson, Declan T. Bradley

{"title":"Effectiveness of Influenza Vaccines and Duration of Protection Against Hospitalisation During the 2024/25 Season in Northern Ireland, UK","authors":"Magda Bucholc, Siobhán Murphy, Mark G. O'Doherty, Suzanne Wilton, Emma Dickson, Declan T. Bradley","doi":"10.1111/irv.70303","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Background</h3>\n \n <p>Seasonal influenza causes substantial morbidity and hospitalisation each year. We estimated influenza vaccine effectiveness (VE) against laboratory-confirmed influenza-associated hospitalisation among patients in Northern Ireland (NI) during the 2024/25 influenza season.</p>\n </section>\n \n <section>\n \n <h3> Methods</h3>\n \n <p>We used a test-negative design to estimate VE against hospitalisation. Influenza-positive cases and test-negative controls were identified through the national laboratory surveillance system and linked to hospital admission and vaccination records. VE was estimated by influenza type/subtype, age group, sex, vaccine type and time since vaccination.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>Among 15,133 hospitalised patients, 2024 (13.4%) tested positive for influenza. Among the 2024 patients admitted with laboratory-confirmed influenza, the vast majority tested positive for influenza A (<i>n</i> = 1803; 89.1%), whereas 221 cases (10.9%) were influenza B. Subtyping of influenza A identified 606 A(H1) infections and 93 A(H3) infections; the remaining 1104 influenza A samples were not subtyped. VE against laboratory-confirmed influenza infection was 46.0% (95% CI: 39.7% to 51.8%), with higher VE in children aged 2–17 years (60.8%; 95% CI: 48.3% to 70.5%) than in adults aged 18–64 years (40.5%; 95% CI: 24.9% to 53.2%) and ≥ 65 years (42.3%; 95% CI: 33.2% to 50.1%). VE against influenza A across all ages was 41.4% (95% CI: 34.2% to 47.9%). Vaccination reduced the odds of hospitalisation due to influenza A(H1) by 44.3% (95% CI: 33.2% to 53.7%) and A(H3) by 49.9% (95% CI: 20.3% to 69.3%). VE against influenza B was higher at 76.4% (95% CI: 64.9% to 84.7%). For influenza A, VE was highest 2–8 weeks after vaccination at 51.9% (95% CI: 42.1% to 60.1%) and declined with time since vaccination to 44.6% (95% CI: 35.6% to 52.5%) at 9–16 weeks and 41.4% (95% CI: 15.4% to 60.1%) at ≥ 16 weeks. VE against influenza B remained high throughout the season. No statistically significant differences in VE by vaccine type were found.</p>\n </section>\n \n <section>\n \n <h3> Conclusions</h3>\n \n <p>Influenza vaccination reduced the risk of hospitalisation with laboratory-confirmed influenza during the 2024/25 season, offering meaningful protection at individual and population levels, with the greatest benefit observed in children.</p>\n </section>\n </div>","PeriodicalId":13544,"journal":{"name":"Influenza and Other Respiratory Viruses","volume":"20 8","pages":""},"PeriodicalIF":3.9000,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13446018/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Influenza and Other Respiratory Viruses","FirstCategoryId":"3","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/irv.70303","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"INFECTIOUS DISEASES","Score":null,"Total":0}

引用次数: 0

Abstract

Background

Seasonal influenza causes substantial morbidity and hospitalisation each year. We estimated influenza vaccine effectiveness (VE) against laboratory-confirmed influenza-associated hospitalisation among patients in Northern Ireland (NI) during the 2024/25 influenza season.

Methods

We used a test-negative design to estimate VE against hospitalisation. Influenza-positive cases and test-negative controls were identified through the national laboratory surveillance system and linked to hospital admission and vaccination records. VE was estimated by influenza type/subtype, age group, sex, vaccine type and time since vaccination.

Results

Among 15,133 hospitalised patients, 2024 (13.4%) tested positive for influenza. Among the 2024 patients admitted with laboratory-confirmed influenza, the vast majority tested positive for influenza A (n = 1803; 89.1%), whereas 221 cases (10.9%) were influenza B. Subtyping of influenza A identified 606 A(H1) infections and 93 A(H3) infections; the remaining 1104 influenza A samples were not subtyped. VE against laboratory-confirmed influenza infection was 46.0% (95% CI: 39.7% to 51.8%), with higher VE in children aged 2–17 years (60.8%; 95% CI: 48.3% to 70.5%) than in adults aged 18–64 years (40.5%; 95% CI: 24.9% to 53.2%) and ≥ 65 years (42.3%; 95% CI: 33.2% to 50.1%). VE against influenza A across all ages was 41.4% (95% CI: 34.2% to 47.9%). Vaccination reduced the odds of hospitalisation due to influenza A(H1) by 44.3% (95% CI: 33.2% to 53.7%) and A(H3) by 49.9% (95% CI: 20.3% to 69.3%). VE against influenza B was higher at 76.4% (95% CI: 64.9% to 84.7%). For influenza A, VE was highest 2–8 weeks after vaccination at 51.9% (95% CI: 42.1% to 60.1%) and declined with time since vaccination to 44.6% (95% CI: 35.6% to 52.5%) at 9–16 weeks and 41.4% (95% CI: 15.4% to 60.1%) at ≥ 16 weeks. VE against influenza B remained high throughout the season. No statistically significant differences in VE by vaccine type were found.

Conclusions

Influenza vaccination reduced the risk of hospitalisation with laboratory-confirmed influenza during the 2024/25 season, offering meaningful protection at individual and population levels, with the greatest benefit observed in children.

查看原文本刊更多论文

联合王国北爱尔兰在2024/25流感季节期间流感疫苗的有效性和预防住院的持续时间。

背景：季节性流感每年导致大量发病率和住院。我们估计了流感疫苗对北爱尔兰（NI）在2024/25流感季节实验室确诊的流感相关住院患者的有效性（VE）。方法：我们采用阴性试验设计来估计VE与住院的关系。流感阳性病例和检测阴性对照是通过国家实验室监测系统确定的，并与住院和疫苗接种记录相关联。根据流感类型/亚型、年龄组、性别、疫苗类型和接种后的时间来估计VE。结果：15133例住院患者中，2024例（13.4%）流感检测呈阳性。在2024例经实验室确诊的流感患者中，绝大多数甲型流感检测呈阳性（1803例，占89.1%），而乙型流感检测为221例（10.9%）。甲型流感亚型鉴定为甲型H1感染606例，甲型H3感染93例；其余1104份甲型流感样本没有亚型。实验室确诊流感感染的VE为46.0% (95% CI: 39.7%至51.8%)，2-17岁儿童的VE （60.8%, 95% CI: 48.3%至70.5%）高于18-64岁（40.5%,95% CI: 24.9%至53.2%）和≥65岁（42.3%,95% CI: 33.2%至50.1%）的成年人。所有年龄段抗甲型流感的VE为41.4% （95% CI: 34.2%至47.9%）。接种疫苗可使甲型流感（H1）住院率降低44.3% (95% CI: 33.2%至53.7%)，甲型流感（H3）住院率降低49.9% （95% CI: 20.3%至69.3%）。抗乙型流感的VE较高，为76.4% （95% CI: 64.9% ~ 84.7%）。对于甲型流感，疫苗接种后2-8周VE最高，为51.9% (95% CI: 42.1%至60.1%)，随着接种时间的推移，疫苗接种后9-16周VE下降至44.6% (95% CI: 35.6%至52.5%)，≥16周VE下降至41.4% （95% CI: 15.4%至60.1%）。乙型流感的流感病毒抗体在整个季节仍然很高。不同疫苗类型间VE差异无统计学意义。结论：流感疫苗接种降低了在2024/25流感季节因实验室确诊流感住院的风险，在个人和人群层面提供了有意义的保护，在儿童中观察到最大的益处。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Influenza and Other Respiratory Viruses 医学-病毒学

CiteScore

7.20

自引率

4.50%

发文量

120

审稿时长

6-12 weeks

期刊介绍： Influenza and Other Respiratory Viruses is the official journal of the International Society of Influenza and Other Respiratory Virus Diseases - an independent scientific professional society - dedicated to promoting the prevention, detection, treatment, and control of influenza and other respiratory virus diseases. Influenza and Other Respiratory Viruses is an Open Access journal. Copyright on any research article published by Influenza and Other Respiratory Viruses is retained by the author(s). Authors grant Wiley a license to publish the article and identify itself as the original publisher. Authors also grant any third party the right to use the article freely as long as its integrity is maintained and its original authors, citation details and publisher are identified.