Chen LL, Zhang X, Zhang K, Chan BP, Yuk Yuen JK, Y. Risk assessment of 2024 cattle H5N1 using age-stratified serosurveillance data. Emerg Microbes Infect. 2025 Apr 22:2497304
The highly pathogenic avian influenza virus A(H5N1) clade 2.3.4.4b has caused a human outbreak in North America since March 2024. Here, we conducted a serosurveillance study to determine the risk of A(H5N1) clade 2.3.4.4b (2024 cattle H5N1) to general population. In the initial screening of 180 serum specimens encompassing all age groups, 2.2% (4/180) had detectable neutralizing antibody (nAb) titers against reverse genetics-derived 2024 cattle H5N1, with all collected from older adults aged ≥60 years old. Further screening showed that 4.2% (19/450) of adults aged ≥60 years old had detectable nAb titers against the 2024 cattle H5N1. 80% (4/5) serum specimens with nAb titer of ≥40 had detectable HI titer, and there was a positive correlation between nAb titer and HA binding (r = 0.3325, 95% confidence interval 0.2477 to 0.4123; P < 0.0001). The nAb titer against seasonal H1N1 virus was 4.2-fold higher for ≥60 years old individuals with detectable H5N1 nAb titer than those ≥60 years old ones without (geometric mean titer: 89.3 [95% CI 42.9-185.7]) vs 21.3 [95% CI 17.3-26.1], P < 0.0001), but there was no statistically significant difference between H5N1 and H3N2 nAb titer. There was no difference in demographics, comorbidities and clinical frailty scores between individuals with detectable H5N1 nAb and those without. Our findings suggest that most individuals lack nAb response against 2024 cattle H5N1 and there is an urgency to develop and evaluate H5N1 vaccine or prophylactic monoclonal antibodies. Immune imprinting may be responsible for the cross neutralization between H5N1 and H1N1 among older adults.
See Also:
Latest articles in those days:
- Engineered Bacillus subtilis to deliver dsRNA via extracellular vesicles against the H9N2 avian influenza virus 3 hours ago
- [preprint]Spatiotemporal dynamics and ecological risk factors of highly pathogenic avian influenza A(H5N1) in Canadian wildlife: A One Health surveillance analysis 3 hours ago
- Epidemiological and Virological Characteristics of H9N2 Avian Influenza Virus in Jiangsu Province, China, 2024 15 hours ago
- Innate Pathway Selection Modulates Antibody and T-Cell Responses to Mosaic Influenza Nucleoprotein in Cattle 1 days ago
- Game Over for the Baseline: Influenza Hospitalization Patterns Before, During, and After the COVID-19 Pandemic (FluSurv-NET, 2009–2025) 1 days ago
[Go Top] [Close Window]


