Evidence map›Paper›PMID 41589063›Full record

ArticleThe Journal of infectious diseases2026

Influenza Vaccination Effectiveness Against Influenza-Associated Hospitalization in Children and the Effects of Repeated Vaccination.

Xuan Yu, So-Lun Lee, Mike Y W Kwan, Shuyi Zhong, Caitriona Murphy, Eunice L Y Chan, Joshua S C Wong, Sheena G Sullivan, Malik Peiris, Benjamin J Cowling

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in The Journal of infectious diseases, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

10 authors.

Xuan YuWorld Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China.ORCID 0009-0008-8840-3029
So-Lun LeeDepartment of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
Mike Y W KwanDepartment of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong Special Administrative Region, China.
Shuyi ZhongWorld Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China.ORCID 0000-0002-4374-5921
Caitriona MurphyWorld Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China.ORCID 0009-0004-6570-0582
Eunice L Y ChanDepartment of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
Joshua S C WongDepartment of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong Special Administrative Region, China.
Sheena G SullivanSchool of Clinical Sciences, Monash University, Melbourne, VIC, Australia.ORCID 0000-0002-0856-0294
Malik PeirisCentre for Immunology & Infection, Hong Kong Science and Technology Park, New Territories, Hong Kong Special Administrative Region, China.
Benjamin J CowlingWorld Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China.ORCID 0000-0002-6297-7154

Funding

Government of the Hong Kong Special Administrative Region INF-HKU-3Health and Medical Research FundHealth BureauUniversity Grants Committee HKU SRFS2021-7S03
6 · The paper itself

Abstract

backgroundGiven concerns that influenza vaccine effectiveness (VE) might differ with repeated annual vaccination, we estimated VE against influenza-associated hospitalization and assessed repeat vaccination effects.

methodsWe analyzed a test-negative design study conducted in 3 Hong Kong hospitals (October 2015 - July 2025), excluding the 2020/21 and 2021/22 seasons due to the absence of influenza circulation during the COVID-19 pandemic. Polymerase chain reaction testing was used to identify influenza virus infections. We used conditional logistic regression to estimate influenza VE overall, by influenza type/subtype, and by influenza vaccination status in the preceding year (repeat vaccination status).

resultsWe analyzed data on 34 237 children, among whom 5245 (15.3%) tested positive for influenza. VE against influenza-associated hospitalization was 57.2% (95% confidence interval [CI]: 52.3%, 61.6%), with subtype-specific VE estimates of 67.7% (95% CI: 61.8%, 72.7%) for A(H1N1)pdm09, 60.6% (95% CI: 50.8%, 68.5%) for influenza B, and 37.2% (95% CI: 24.7%, 47.6%) for A(H3N2). The overall ΔVE (repeated VE - current only VE) was -13.6% (95% CI: -33.2%, 3.2%), indicating lower VE among repeatedly vaccinated children.

conclusionsCurrent influenza vaccination programs provide substantial protection, but could be further improved by strategies that mitigate repeat vaccination effects, and further research is needed to identify such strategies.

Indexed as

HospitalizationInfluenza, HumanInfluenza VaccinesVaccine EfficacyAdolescentChildChild, PreschoolFemaleHong KongHumansInfantInfluenza A Virus, H1N1 SubtypeInfluenza A Virus, H3N2 SubtypeInfluenza B virusMaleVaccinationInfluenza VaccinesA(H1N1)pdm09influenzarepeat vaccinationvaccinationvaccine effectiveness

Identifiers

PMID41589063
PMCPMC13271378

What OpenQuestion holds

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LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.