Viral immunologyPub Date : 2026-08-01Epub Date: 2026-05-20DOI: 10.1177/08828245261445782
Danyal Imani, Navid Dashti, Amir Peymani, Ali Soltani, Masoud Hassanzadeh Makoui
{"title":"Effect of Pentoxifylline on Inflammatory Markers in COVID-19: A Meta-Analysis of Randomized Controlled Trials.","authors":"Danyal Imani, Navid Dashti, Amir Peymani, Ali Soltani, Masoud Hassanzadeh Makoui","doi":"10.1177/08828245261445782","DOIUrl":"10.1177/08828245261445782","url":null,"abstract":"<p><p>The hyperinflammatory response in COVID-19 is a major factor contributing to morbidity. Pentoxifylline, a methylxanthine derivative, has immunomodulatory properties, but its effects on inflammatory markers in COVID-19 remain unclear. This meta-analysis aims to evaluate the efficacy of pentoxifylline supplementation on CRP and interleukin-6 (IL-6) levels in these patients. A systematic search was conducted across multiple databases for randomized controlled trials (RCTs) published up to September 2025. Four RCTs, including 178 cases and 321 controls for CRP, and two RCTs, including 70 cases and 70 controls for IL-6, were included. Two reviewers independently performed data extraction and assessed the risk of bias using the Cochrane tool. Pooled standardized mean differences (SMDs) were calculated using a random-effects model. Heterogeneity was analyzed through meta-regression, and the conclusiveness of the evidence was evaluated using Trial Sequential Analysis (TSA). Pentoxifylline did not significantly reduce C-reactive protein (CRP) levels compared to the control group (SMD = -0.89; 95% CI: -1.85 to 0.07; <i>p</i> = 0.07). However, substantial heterogeneity was noted across the studies (<i>I<sup>2</sup> =</i> 95.3%). Similarly, a nonsignificant trend toward reduction was observed for IL-6 (SMD = -0.22; 95% CI: -0.96 to 0.52; <i>p</i> = 0.55), accompanied by significant heterogeneity (<i>I<sup>2</sup> =</i> 79.1%). Given the limited number of studies included, the results are inherently fragile, and one additional trial could substantially shift the pooled estimate. Meta-regression analysis indicated that patient age and publication year did not account for the heterogeneity, although there was a nonsignificant trend suggesting that a longer treatment duration might be associated with greater CRP reduction. TSA for CRP showed that cumulative evidence suggested futility and a lack of meaningful effect, confirming a significant lack of effect. The included studies generally had a low risk of attrition and reporting bias. Current evidence does not support the use of pentoxifylline for significantly reducing CRP or IL-6 levels in COVID-19 patients. The findings regarding CRP are considered conclusive, but the limited number of studies suggests that further trials on this outcome may alter this conclusion.</p>","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"223-231"},"PeriodicalIF":1.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147975822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Viral immunologyPub Date : 2026-08-01Epub Date: 2026-05-11DOI: 10.1177/08828245261449701
Elham Mohammed Khatrawi, Syed Yasir Ali, Syed Luqman Ali, Hind Althagafi
{"title":"A Robust Defense Against IPNV and VHSV by Designing Revolutionary Multi-Epitope Vaccine Utilizing Immunoinformatics Approaches.","authors":"Elham Mohammed Khatrawi, Syed Yasir Ali, Syed Luqman Ali, Hind Althagafi","doi":"10.1177/08828245261449701","DOIUrl":"10.1177/08828245261449701","url":null,"abstract":"<p><p>In the intricate world of aquatic ecosystems, infectious pancreatic necrosis virus (IPNV) and viral hemorrhagic septicemia virus (VHSV) emerge as formidable threats to marine life, posing diverse diseases that reverberate through shared host species (Salmon, trout fishes). The coexistence of these viruses amplifies health risks, compelling the pursuit of inventive intervention strategies. Recognizing the urgency, a current and optimistic initiative strives to craft a revolutionary combined vaccine, offering protection against both IPNV and VHSV. This innovative endeavor, driven by an immunoinformatics approach, identifies immune-dominant epitopes from CadB and LamB proteins, ensuring the final vaccine's immunogenicity, non-allergenicity, and enhanced solubility. Molecular dynamics simulations validate its binding stability and structural integrity. In a pivotal move, codon optimization using <i>Escherichia coli</i> K12 as a model result in an ideal guanine-cytosine content and a higher Codon Adaptation Index value, seamlessly integrating into the cloning vector pET2+ (a). In essence, our outcomes underscore the potential of this proposed peptide vaccine to elicit a robust immune response against both IHNV and VHSV, marking a breakthrough in the holistic management of infectious diseases in aquatic environments.</p>","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"205-222"},"PeriodicalIF":1.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147869733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Prevalence of SEN Virus-D and SEN Virus-H Among Hemodialysis Patients in Diyala Province.","authors":"Ibtihal Hameed Mohsin, Ansam Dawod Salman, Luma Ghaeb Alsaadi","doi":"10.1177/08828245261438006","DOIUrl":"10.1177/08828245261438006","url":null,"abstract":"<p><p>The SEN virus (SENV), a DNA virus that has been linked to blood transfusion, is a major cause of post-transfusion hepatitis. SENV-D and SENV-H are non-A to E hepatitis viruses. The present study was conducted to investigate the prevalence of SENV-D/H among dialysis patients and blood donors as control group in Diyala province/Iraq. This study includes 120 participants: 80 dialysis patients who have been attending the Ibn-Sina Dialysis Center-Diyala Directorate of Health were previously diagnosed with the disease, and 40 individuals as controls were selected at random from blood donors at the Central Blood Bank during the period from 1/5/2025 to 30/11/2025. Full information had been taken directly from the patients, and the information had been arranged in an informative formula sheet, which includes age and gender. All study subjects were screened for nested polymerase chain reaction. The SENV-D prevalence was 10 (12.50%) and 0.00% for dialysis patients and controls, respectively, and SENV-H was 5 (6.25%) and 1 (2.50%) for dialysis patients and controls, respectively. The SENV co-infection rate of genotypes D and H was 3 (7.50%) in the dialysis group, and no cases in the control group were found. A very strong association was found between the distinct SENV genotypes and Hepatitis B virus (HBV) or Hepatitis C virus (HCV) status. Positivity for SENV was also correlated with high serum Aspartate Aminotransferase (AST) and Alanine aminotransferase (ALT). SENV-D and SENV-H were more prevalent among hemodialysis patients than in normal blood donors. The presence of SEN-V in both groups indicates its categorization as a blood-borne virus and suggests risk for transmission by blood exposure.</p>","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"177-183"},"PeriodicalIF":1.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147575398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Viral immunologyPub Date : 2026-06-01Epub Date: 2026-04-23DOI: 10.1177/08828245261445779
Muhammed Furkan Kürkçü, Gaye Ebru Şeker, Duray Şeker, Ayfer Bakır
{"title":"Bovine Leukemia Virus Prevalence in Women with Breast Cancer and Premalignant Breast Lesions.","authors":"Muhammed Furkan Kürkçü, Gaye Ebru Şeker, Duray Şeker, Ayfer Bakır","doi":"10.1177/08828245261445779","DOIUrl":"10.1177/08828245261445779","url":null,"abstract":"<p><p>The potential role of bovine leukemia virus (BLV), a zoonotic deltaretrovirus, in human breast carcinogenesis remains controversial, and evidence from seroepidemiological studies is limited. This study aimed to evaluate BLV IgG seroprevalence in women with malignant breast cancer and benign breast lesions and to explore the possible association between BLV exposure and breast cancer development. In this cross-sectional comparative study, a total of 124 women aged ≥18 years who presented to Ankara Etlik City Hospital between May and July 2024 were included. The malignant group comprised 82 women with histopathologically confirmed breast cancer, while the control group included 42 women with benign breast lesions. Serum samples were analyzed for BLV-specific IgG antibodies using a commercial enzyme-linked immunosorbent assay kit. Overall BLV IgG seroprevalence was 12.9% (16/124), with rates of 13.4% in the malignant group and 11.9% in the benign group, showing no statistically significant difference (<i>p</i> = 0.812). In the malignant group, BLV IgG seropositive patients were significantly older than seronegative patients, and seropositivity increased with age (<i>p</i> < 0.01). Although higher BLV IgG seropositivity were observed in invasive mucinous carcinoma cases, this association did not reach statistical significance in logistic regression analysis. Hematological parameters were evaluated to investigate potential systemic immune or inflammatory responses associated with BLV exposure; however, no significant associations were identified between BLV IgG seropositivity and these parameters. These findings suggest that BLV exposure, as reflected by humoral immune response, is not directly associated with breast cancer development but may represent cumulative or long-term exposure. Further large-scale, multicenter studies integrating molecular and serological approaches are warranted to clarify the potential role of BLV in human breast cancer etiology.</p>","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"192-199"},"PeriodicalIF":1.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147782847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Viral immunologyPub Date : 2026-06-01Epub Date: 2026-04-23DOI: 10.1177/08828245261444539
Zoi Thomou, Chrysostomos I Dovas, Theofilos Poutahidis, Anagnostis Argiriou, Evangelia Mouchtaropoulou, Konstantinos Zaralis, Jacobus Johannes Hendrik Koenen, Serafeim C Chaintoutis
{"title":"Maternal SARS-CoV-2 Antibodies in Mink Kits: Dynamics of Passive Immunity and Implications for Silent Farm-Wide Transmission Following Virus Re-Incursion.","authors":"Zoi Thomou, Chrysostomos I Dovas, Theofilos Poutahidis, Anagnostis Argiriou, Evangelia Mouchtaropoulou, Konstantinos Zaralis, Jacobus Johannes Hendrik Koenen, Serafeim C Chaintoutis","doi":"10.1177/08828245261444539","DOIUrl":"10.1177/08828245261444539","url":null,"abstract":"<p><p>Maternal antibodies protect mink kits early in life, but their duration and impact on subsequent SARS-CoV-2 exposure remain unclear. We longitudinally characterized passive immunity in kits born to mothers previously infected with lineage B.1.1.305 on a commercial farm in Greece and related antibody kinetics to a later heterologous virus incursion. Breeder animals showed a 93.3% seropositivity rate after the initial outbreak. On day 20 postpartum, 81.4% of mothers and 69.8% of kits were positive for SARS-CoV-2 nucleocapsid (N)-specific antibodies by enzyme-linked immunosorbent assay (ELISA); a maternal S/P% >160.1% was associated with kit seropositivity at the same time-point (area under the curve 0.985; sensitivity 90%; specificity 100%). Kit seropositivity declined to 2.4% by D*56, consistent with the rapid waning of maternally derived antibodies. On D*87, 97.6% of kits had seroconverted, and 90.0% of mothers were seropositive; Analysis of oropharyngeal swabs by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and next generation sequencing (NGS) confirmed introduction of lineage B.1.177. No clinical signs or excess mortality were observed during this reinfection event. These data demonstrate efficient passive transfer, rapid loss of detectable antibodies by ∼8 weeks, and farm-wide seroconversion after re-exposure to a new lineage. The absence of disease despite widespread seroconversion suggests maternally acquired immunity may have mitigated illness but did not prevent infection. Silent SARS-CoV-2 circulation can therefore occur in partially immune mink farms, with important implications for biosecurity and targeted SARS-CoV-2 surveillance. To our knowledge, this is the first longitudinal study to track the dynamics of maternally derived SARS-CoV-2 antibodies in mink kits and link them to subsequent exposure outcomes.</p>","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"184-191"},"PeriodicalIF":1.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147782754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Viral immunologyPub Date : 2026-05-01Epub Date: 2026-03-07DOI: 10.1177/08828245261429121
Carlos Emilio Miguel-Rodríguez, Jesús Iván Antonio-Buendia, Ana Lorena Gutierrez-Escolano, Leopoldo Santos-Argumedo
{"title":"LPS and IL-4 Stimulation Favor Murine Norovirus Infection of B Cells.","authors":"Carlos Emilio Miguel-Rodríguez, Jesús Iván Antonio-Buendia, Ana Lorena Gutierrez-Escolano, Leopoldo Santos-Argumedo","doi":"10.1177/08828245261429121","DOIUrl":"10.1177/08828245261429121","url":null,"abstract":"<p><p>Noroviruses are single-stranded positive-polarity RNA viruses classified in the family Caliciviridae. Human noroviruses (HuNoVs) are a leading cause of acute viral gastroenteritis worldwide. Despite their ability to infect various epithelial and nonepithelial cell types, establishing robust <i>in vitro</i> culture systems for HuNoVs remains challenging. As a result, murine norovirus 1 (MNV-1) has become a widely used model for investigating norovirus biology and pathogenesis, due to its ability to replicate efficiently in primary dendritic cells and macrophages. Although different B-cell lines are susceptible to MNV-1 infection, the susceptibility of primary B lymphocytes has been poorly characterized. Here, we demonstrate that MNV-1 infects primary B lymphocytes, with infection levels increased by prior stimulation with lipopolysaccharide and interleukin-4. The enhanced infection does not appear to result from increased virion binding but instead to an increased cellular permissiveness. These findings provide new insights into the cellular tropism of MNV-1 and suggest that the activation status of B-cell influences their susceptibility to infection. This model may improve our understanding of norovirus-host-cell interactions in adaptive immune cells and could aid in the development of more representative <i>in vitro</i> systems for studying norovirus pathogenesis.</p>","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"150-157"},"PeriodicalIF":1.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147373085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Viral immunologyPub Date : 2026-05-01Epub Date: 2026-03-19DOI: 10.1177/08828245261428999
{"title":"Expression of Concern: \"Variations in the S and P Regions of the Hepatitis B Virus Genome Under Immunosuppression <i>In Vitro</i> and <i>In Vivo</i>\".","authors":"","doi":"10.1177/08828245261428999","DOIUrl":"10.1177/08828245261428999","url":null,"abstract":"","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"141"},"PeriodicalIF":1.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13535600/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147487684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Serological Markers and EBV DNA of Epstein-Barr Virus Infection in a Health Examination Cohort from Chongqing, China.","authors":"Zhuojun Ou, Cong Wang, Peng Zhao, Lanxin Peng, Jing Tan, Yu He, Yu Xiang","doi":"10.1177/08828245261426990","DOIUrl":"10.1177/08828245261426990","url":null,"abstract":"<p><p>This study aimed to characterize Epstein-Barr virus (EBV) serological markers and EBV DNA profiles in a healthy examination cohort from Chongqing, China, and to examine their associations with routine hematological and biochemical parameters. This retrospective cross-sectional study included adults undergoing routine health examinations in Chongqing between 2019 and 2024. EBV serology (EA-IgA and VCA-IgA) was assessed in 4,535 individuals using ELISA, and EBV DNA was measured in 6,508 individuals by quantitative PCR. Hematological indices and liver and renal function markers were compared across EBV antibody subgroups and EBV DNA status. Multivariable linear regression analyses were performed with adjustment for age and sex. VCA-IgA seroprevalence was significantly higher than EA-IgA (13.38% vs. 6.09%, <i>p</i> < 0.001), with both peaking in the 41-50-year age group. EBV DNA was detected in 7.24% of individuals, with positivity increasing with age (≥61 years: 12.09%) and being higher in males than females (7.81% vs. 6.06%, <i>p</i> = 0.010). Among EBV DNA-positive individuals, 86.17% had low viral loads (<10<sup>4</sup> copies/mL). After adjustment, EBV seropositivity and EBV DNA positivity were independently associated with statistically significant differences in leukocyte subsets and hepatic and renal markers; however, all median values remained within established clinical reference ranges. EBV infection markers in this inland Chinese health examination population exhibited distinct age- and sex-related distributions and showed independent associations with subtle physiological variations rather than overt pathology. Importantly, EBV serological markers and EBV DNA demonstrated differential association patterns, indicating that they convey complementary and nonredundant biological information in assessing EBV infection status.</p>","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"142-149"},"PeriodicalIF":1.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147356874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Single-Cell and Mendelian Randomization Analyses Identify Key Genes Common to COVID-19 and Multiple Sclerosis.","authors":"Shuping Chen, Jun Ruan, Sikai Cheng, Huifang Zheng, Tianyu Chang, Guichun Bao, Zijing Zhu, Xinglin Li, Wei Zhao, Kunwen Zheng","doi":"10.1177/08828245261426986","DOIUrl":"10.1177/08828245261426986","url":null,"abstract":"<p><p>The pathophysiology of multiple sclerosis (MS) bears notable similarities to the dysregulated inflammatory response occurring during coronavirus disease 2019 (COVID-19) infection. B cells play a pivotal role among immune cells in the pathogenesis of both these diseases. Consequently, clarifying the molecular mechanism underlying B cell function in COVID-19 and MS is of great significance for formulating more efficient treatment strategies. A comprehensive analysis integrating single-cell RNA sequencing (scRNA-seq), genome-wide association study, and expression quantitative trait locus data from patients with COVID-19 and MS was performed. Gene set enrichment analysis revealed pathways and functional roles associated with the key genes, while pseudotime analysis tracked their expression patterns across different B cell developmental trajectories. The results of scRNA-seq analysis showed that, in comparison with the healthy control group, the proportion of B cells rose in patients with COVID-19 and those with MS. Through differential expression analysis and Mendelian randomization analysis, <i>DR1</i>, <i>IKZF3</i>, and <i>RUVBL2</i> were identified as risk factors for both COVID-19 and MS, whereas <i>ANAPC5</i> was characterized as a protective factor against these two conditions. The findings of the pseudotime analysis indicated that only <i>IKZF3</i> had differential expression across different branches of B cells. <i>IKZF3</i>'s role in promoting immune inflammation and inhibiting metabolism could potentially be linked to the onset and comorbidity of COVID-19 and MS. This emphasizes not only the possible interaction mechanisms between these two diseases but also their clinical significance.</p>","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"158-169"},"PeriodicalIF":1.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147499817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Viral immunologyPub Date : 2026-05-01Epub Date: 2026-02-16DOI: 10.1177/08828245261424908
Yulei Li, Xinyue Zhang, Xuan Zhou, Xiaoying Zhu, Liuchun Tan, Zhongmin Pan, Zhengxin Huang, Jiannan Lv, Demin Cao
{"title":"Cross-Reactive Antibody Responses to Emerging Bovine H5N1 Clade 2.3.4.4b Following Seasonal Influenza Vaccination: Implications for Pandemic Preparedness.","authors":"Yulei Li, Xinyue Zhang, Xuan Zhou, Xiaoying Zhu, Liuchun Tan, Zhongmin Pan, Zhengxin Huang, Jiannan Lv, Demin Cao","doi":"10.1177/08828245261424908","DOIUrl":"10.1177/08828245261424908","url":null,"abstract":"<p><strong>Background: </strong>The emergence of highly pathogenic avian influenza A (H5N1) clade 2.3.4.4b in dairy cattle and human cases raises urgent pandemic concerns. A critical question is whether seasonal influenza vaccines elicit cross-reactive immunity against this novel zoonotic strain, potentially contributing to pre-existing population immunity.</p><p><strong>Methods: </strong>We combined structural bioinformatics and serological analysis. Hemagglutinin (HA) protein sequence and structural conservation were assessed between World Health Organization WHO-recommended 2024-2025 vaccine strains (H1N1 A/Victoria/4897/2022, H3N2 A/Thailand/8/2022) and bovine H5N1 (A/Texas/37/2024). Cross-reactive antibodies were measured in serum from 46 vaccinated individuals using ELISA against A/Texas/37/2024 HA. Endpoint titers were the highest reciprocal dilution with absorbance >2.1-fold background. Statistical analyses included Pearson correlation (age, dose, time) and Wilcoxon rank-sum/Chi-squared tests (group comparisons).</p><p><strong>Results: </strong>Structural analysis revealed 79.3% amino acid identity in the HA2 subunit between H1N1 and H5N1, with conserved epitopes in the stalk domain. Serologically, 41.3% (19/46) of vaccinated individuals had cross-reactive HA-binding antibodies with titers ≥1,280. No significant associations were found with sex, vaccine type, brand, or number of doses. A significant positive correlation existed between age and antibody titer (Pearson's <i>R</i> = 0.51, <i>p</i> < 0.001); individuals over 60 years had higher titers than younger groups.</p><p><strong>Conclusions: </strong>Seasonal influenza vaccination is associated with cross-reactive HA-binding antibodies against bovine H5N1 clade 2.3.4.4b in a substantial proportion of individuals, with responses increasing with age. This suggests pre-existing immunity from vaccination or prior exposures may influence responses to this zoonotic threat. However, the functional neutralizing capacity and protective efficacy of these antibodies are unproven. These findings highlight the potential immunological footprint of current vaccines against emerging strains and support further investigation into cross-protection. They also reinforce the importance of conserved HA epitopes as targets for next-generation universal influenza vaccines.</p>","PeriodicalId":23665,"journal":{"name":"Viral immunology","volume":" ","pages":"133-140"},"PeriodicalIF":1.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146202953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}