Evidence map›Paper›PMID 41332001›Full record

ArticleJournal of veterinary science2025

Development of an H9N2 vaccine strain with enhanced neuraminidase immunogenicity via dual hemagglutinin and neuraminidase modification.

Jin-Ha Song, Seung-Eun Son, Howon Kim, Seung-Ji Kim, Se-Hee An, Chung-Young Lee, Kang-Seuk Choi, Hyuk-Joon Kwon

Abstract read
In one paragraph

Article in Journal of veterinary science, 2025. 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

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

8 authors.

Jin-Ha SongLaboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.ORCID https://orcid.org/0000-0002-1814-2504
Seung-Eun SonLaboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.ORCID https://orcid.org/0000-0002-4558-8990
Howon KimLaboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.ORCID https://orcid.org/0000-0002-5509-1152
Seung-Ji KimLaboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.ORCID https://orcid.org/0000-0001-8215-8669
Se-Hee AnAvian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea.ORCID https://orcid.org/0000-0002-2206-1299
Chung-Young LeeDepartment of Microbiology, College of Medicine, Kyungpook National University, Daegu 41944, Korea.ORCID https://orcid.org/0000-0003-3037-7581
Kang-Seuk ChoiLaboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.ORCID https://orcid.org/0000-0001-6825-6924
Hyuk-Joon KwonLaboratory of Poultry Medicine, Department of Farm Animal Medicine, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, Seoul 08826, Korea.ORCID https://orcid.org/0000-0001-9107-7860

Funding

Animal and Plant Quarantine Agency Z-1543418-2021-22-0102Korea Health Industry Development Institute HV20C0000Korea Health Industry Development Institute RS-2000-KH000000Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry RS-2024-00399869National Research Foundation of Korea NRF-2022M3A9I2017587National Research Foundation of Korea RS-2024-00443043
6 · The paper itself

Abstract

importanceThe Y439 lineage 01310 E20 H9N2 vaccine strain currently used in South Korea has undergone extensive egg adaptation, resulting in substantial changes, including an 18-amino acid neuraminidase (NA) stalk deletion. Additionally, both early and late 01310 passages inherently harbor an N-glycan at hemagglutinin (HA) residue 158-160 (HA158) that may interfere with virus-specific antibodies.

objectiveWe aimed to develop a high-yield vaccine strain without egg passaging and to overcome the limitations of the conventional vaccine strain that may compromise immunogenicity.

methodsWe introduced a genetically modified 01310 PB2 gene (310-MVV: I66M, I109V, I133V) to increase replication in embryonated eggs and removed the N-glycan at HA158 and restored the NA stalk to improve immunogenicity. The resulting strain was assessed for egg replication and immunogenicity in chickens.

resultsThe resulting vaccine strain (310-SNS-193D-MVV) grew efficiently in embryonated eggs without repeated passaging. As restoring the NA stalk alone was insufficient to enhance NA-specific immunity, simultaneously removing the N-glycan at HA158 markedly increased NA-specific antibody responses and neutralizing antibody titers across multiple H9N2 lineages. Additionally, incorporating 310-SNS-193D-MVV into a bivalent formulation with a Y280 lineage strain conferred broader coverage without evidence of immune interference. CONCLUSIONS AND RELEVANCE: These findings underscore how PB2, HA, and NA targeted genetic modifications can improve H9N2 vaccine productivity and immunogenicity. These strategies are not limited to our H9N2 strain and can be applied to other low propagating or NA stalk-deleted virus strains.

Indexed as

ChickensHemagglutinin Glycoproteins, Influenza VirusInfluenza A Virus, H9N2 SubtypeInfluenza in BirdsInfluenza VaccinesNeuraminidasePoultry DiseasesAnimalsChick EmbryoImmunogenicity, VaccineHemagglutinin Glycoproteins, Influenza VirusInfluenza VaccinesNeuraminidasecross protectionInfluenza A virus, H9N2 subtypeneuraminidasevaccines, inactivatedvirus replication

Identifiers

PMID41332001
PMCPMC12703918

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LicenceCC BY-NC
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Registered trials

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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.