ArticleEuro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin2026
Moderate protection from vaccination against influenza A(H3N2) subclade K in Beijing, China, September to December 2025.
Article in Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It has been retracted, and should not be counted. Cited by 5 papers.
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.
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.
Who cites it
5 citing papers in PubMed.
- Seasonal vaccine-induced immunity shows preserved cross-reactivity to H3N2 subclade K in adults.EBioMedicine · 2026Article
- Influenza A(H3N2) Subclade K (J.2.4.1): Molecular Characterization, Antigenic Divergence, and Global Spread During the 2025/26 Season.Infectious disease reports · 2026Article
- Human Influenza Virus Infection: A Focus on Key Host Determinants Linked to Clinical Disease Severity.Viruses · 2026Review
- Seasonal vaccine-induced immunity shows preserved cross-reactivity to H3N2 subclade K in adults.medRxiv : the preprint server for health sciences · 2026Article
- Retraction note: Moderate protection from vaccination against influenza A(H3N2) subclade K in Beijing, China, September to December 2025 (Euro Surveill. 2026;31(2)).Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin · 2026Article
Corrections and comments
- Expression of concern
- Retracted
Authors and funding
19 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
During the early 2025/26 influenza season, influenza A(H3N2) subclade K rapidly predominated in Beijing, China. Using a test-negative design, we estimated influenza vaccine effectiveness (VE) among influenza-like illness outpatients tested between September and December 2025. Among 9,579 participants, sequencing of 316 randomly selected A(H3N2)-positive samples showed 84.8% were subclade K, and antigenic analysis of 65 viruses indicated antigenic divergence. Despite this, adjusted VE against laboratory-confirmed influenza was 41.3% (95% CI: 29.2 to 51.3), indicating moderate protection during this subclade K-dominated season.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.