Evidence map›Paper›PMID 41814873›Full record

ArticleInfluenza and other respiratory viruses2026

Influenza Vaccine Effectiveness Against Influenza A(H1N1)pdm09-Associated Hospitalizations With SARI in Beijing, China, in the 2024-2025 Season.

Chunna Ma, Ying Sun, Jiaxin Ma, Yingying Wang, Xiaodi Hu, Ying Shen, Li Zhang, Jiaojiao Zhang, Lu Zhang, Wei Duan and 4 more

Abstract read
In one paragraph

Article in Influenza and other respiratory viruses, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing 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

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

14 authors.

Chunna MaBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Ying SunBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.ORCID https://orcid.org/0000-0002-1113-1407
Jiaxin MaBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Yingying WangBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Xiaodi HuBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Ying ShenBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Li ZhangBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Jiaojiao ZhangBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Lu ZhangBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Wei DuanBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Jia LiBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Quanyi WangBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Daitao ZhangBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.
Peng YangBeijing Research Center for Respiratory Infectious Diseases, Beijing, China.

Funding

Beijing Natural Science Foundation L232014Beijing Research Center for Respiratory Infectious Diseases Project BJRID2025-005Capital's Funds for Health Improvement and Research 2022-1G-3014High Level Public Health Technical Talent Training Plan xuekedaitouren-01-03
6 · The paper itself

Abstract

backgroundIn the 2024-2025 season, influenza activity returned to pre-COVID-19 pandemic levels, with A(H1N1)pdm09 as the predominant subtype. Reassessment vaccine effectiveness (VE) in hospitalized patients is critical to inform potential adjustments to vaccination policy.

methodsUsing a test-negative design, we evaluated the VE of the seasonal influenza vaccine during the 2024-2025 season against A(H1N1)pdm09-associated hospitalizations with severe acute respiratory infections (SARI) in Beijing, China, from December 9, 2024 to February 9, 2025. VE was estimated by comparing the odds of influenza vaccination between case-patients (those testing positive for A(H1N1)pdm09) and controls (influenza test-negative patients), applying inverse-propensity-to-be-vaccinated weights.

resultsThe analysis included 1608 hospitalized SARI patients (17.4% tested positive for A(H1N1)pdm09; 13.8% were vaccinated overall). The adjusted VE against A(H1N1)pdm09-associated hospitalizations was 18.8% (95% CI: 0.9% to 33.6%) overall. Specifically, the VE was 45.4% (95% CI: 10.0% to 67.1%) in children aged 0.5-17 years, 43.8% (95% CI: -20.8% to 76.1%) in adults aged 18-59 years, and 8.6% (95% CI: -15.8% to 27.9%) in older adults ≥ 60 years. Among individuals with chronic conditions, the VE was 18.5% (95% CI: -2.3% to 35.2%) and was higher among those with chronic respiratory conditions (40.6%, 95% CI: -1.7% to 65.7%).

conclusionsDuring the 2024-2025 season in Beijing, the overall VE against A(H1N1)pdm09-associated SARI hospitalizations was suboptimal. However, moderate VE was observed among children and younger adults, while limited effectiveness was seen in the elderly. Optimizing influenza vaccination strategies, including the introduction of high-dose or adjuvanted vaccines to enhance immune response in older adults, is crucial to alleviate influenza-associated hospitalizations.

Indexed as

HospitalizationInfluenza A Virus, H1N1 SubtypeInfluenza, HumanInfluenza VaccinesRespiratory Tract InfectionsVaccine EfficacyAdolescentAdultAgedBeijingChildChild, PreschoolFemaleHumansInfantMaleInfluenza VaccinesChinahospitalizationinfluenzatest‐negative designvaccine effectiveness

Identifiers

PMID41814873
PMCPMC13097499

What OpenQuestion holds

Textmetadata
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.