Guiomar R, Henriques C, Pereira da Silva S, Gomes. Cross-sectional study on protective antibodies against influenza A virus subtypes and cross-protection against influenza A(H3N2) subclade K, Portugal, August 2025. Euro Surveill. 2026 Feb;31(6)
The 2025/26 season was marked by co-circulation of influenza A subtypes, with the first detection of A(H3N2) subclade K in September 2025. In August 2025 in Portugal, 14.8% (95% CI: 12.2-17.8) of 886 persons tested had cross-protective antibodies against this subclade. The overall seroprevalence against circulating A(H1N1)pdm09 strains was 28.1% (95% CI: 24.4-32.0). These data highlight the presence of previous cross-reactive antibodies and the possible advantage of vaccination in the extent of detectable antibodies against influenza viruses.
See Also:
Latest articles in those days:
- Determinants of the Seasonal Influenza Vaccination Uptake Among People Aged 50 Years or Above During and After the Pandemic: A Systematic Review 11 hours ago
- [preprint]A GIS-based framework for standardized environmental characterization in One-Health surveillance: a case study of HPAI monitoring in wetlands 11 hours ago
- First detection and transatlantic introduction of Influenza A(H3N2) subclade K (J.2.4.1) into Ecuador: insights from genomic sentinel surveillance 11 hours ago
- Assessment of influenza virus and coronavirus tropism, replication competence and disease severity in ex vivo and in vitro cultures of the human respiratory tract 1 days ago
- Characterization of bovine-derived H5N1 viruses expressing fluorescent and luminescent reporter proteins 1 days ago
[Go Top] [Close Window]


