Evidence map›Paper›PMID 41711443›Full record

ArticleJournal of virology2026

Impact of an amino acid deletion detected in the hemagglutinin (HA) antigenic site of swine influenza A virus field strains on HA antigenicity.

Taichi Nakano, Mana Esaki, Akiha Inoue, Fumiko Koike, Kosuke Okuya, Makoto Ozawa

Abstract read
In one paragraph

Article in Journal of virology, 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

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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

6 authors.

Taichi NakanoJoint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan.
Mana EsakiJoint Graduate School of Veterinary Medicine, Kagoshima University, Kagoshima, Japan.ORCID 0009-0001-3440-2687
Akiha InoueJoint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan.
Fumiko KoikeSwine Management Consultation K.K., Atsugi, Japan.
Kosuke OkuyaJoint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan.ORCID 0000-0002-7987-9884
Makoto OzawaJoint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan.ORCID 0000-0002-7731-5321

Funding

The Ito Foundation Ken-30
6 · The paper itself

Abstract

Swine influenza A virus (swIAV) is an important pathogen with regard to both the swine industry and public health. The pandemic A(H1N1) 2009 outbreak was caused by the swine-origin pandemic A(H1N1) 2009 [A(H1N1)pdm09] virus. Several reports have shown that several amino acid substitutions in the hemagglutinin (HA) antigenic sites can alter HA antigenicity. However, the impact of the amino acid deletion at position 155 on HA antigenicity remains unknown. In this study, we have isolated 11 samples of swIAVs from seven pig farms in Japan and found an amino acid deletion at position 155 of the HA region in one of the isolates of the H1N2 subtype. To examine the impact of this amino acid deletion on viral replication and HA antigenicity, we generated recombinant influenza A viruses possessing the H1 HA gene encoding either an artificial insertion or deletion of glycine at position 155. The growth kinetics of these recombinant viruses in two different cell lines demonstrated that the effect of amino acid deletion at position 155 of H1 HA on viral replication is limited. In contrast, microneutralization assay-based neutralization titers revealed that amino acid deletion significantly altered HA antigenicity. These results demonstrate that a naturally occurring amino acid deletion at position 155 in an H1 HA antigenic site can markedly alter HA antigenicity with only a limited impact on replication IMPORTANCE: Influenza A viruses circulating in pigs are of major concern because they can reduce herd productivity and sometimes infect humans. Understanding how these viruses change their surface proteins is essential for predicting their evolution and preventing outbreaks. This study focuses on swine influenza A virus isolated from pig farms in Japan and investigates the effect of a specific amino acid deletion in the hemagglutinin protein, which plays a key role in viral recognition by the host immune system. The results show that this deletion does not greatly affect virus growth but markedly alters how the immune system recognizes the virus. Such antigenic changes may allow the virus to evade existing immunity in pig populations and potentially increase the risk of transmission to humans. These findings underscore the need for continued surveillance of such variants in pigs and for future studies to evaluate their possible zoonotic implications.

Indexed as

Antigens, ViralHemagglutinin Glycoproteins, Influenza VirusInfluenza A Virus, H1N1 SubtypeInfluenza A Virus, H1N2 SubtypeOrthomyxoviridae InfectionsSequence DeletionSwine DiseasesAnimalsAntibodies, ViralCell LineJapanSwineVirus ReplicationAntibodies, ViralAntigens, ViralHemagglutinin Glycoproteins, Influenza Virusantigenicityhemagglutininswine influenza

Identifiers

PMID41711443
PMCPMC13011390

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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.