biostudies-literatureCoggon ASCINetNational Institute of Allergy and Infectious DiseasesMinistero della SaluteOak Ridge Institute for Science and EducationBelgian Federal Service for Public HealthAgricultural Research ServiceNIAID NIH HHSNational Institutes of HealthDepartment for Environment, Food and Rural Affairs, UK GovernmentNIH HHSAI centre of Excellencee0030625https://www.ebi.ac.uk/biostudies/studies/S-EPMC12288490biostudies-literatureUnknown99(7)H1 and H3 influenza A viruses (IAVs) circulating in European pigs are markedly distinct from those circulating in other global swine populations. These viruses exhibit significant genetic diversity, further expanded by periodic interspecies transmission of IAVs from humans into pigs, followed by sustained circulation. Several zoonotic IAV infections in humans in Europe have been associated with the 1C lineage of H1 IAVs. Given the predominance of H1 detections in pigs and their zoonotic potential, we quantified antigenic evolution of H1 viruses in European pigs using ferret and pig models and assessed diversity relative to swine IAV vaccine strains. Ferret and swine antisera comparisons revealed no significant differences in antibody responses. Viruses of the 1A.3.3.2 clade exhibited reducJournal of virologyQuantifying the zoonotic risk profile of European influenza A viruses in swine from 2010 to 2020 inclusive.PMC1228849075N593021C0004575N93021C000150201-88888-003-000D0201-88888-002-000D5030-32000-231-000-DSV3041LE 20180092020005DE-SC0014664RF 23/05Herve SRothman RELewis NSVan Reeth KArendsee ZCoggon ARichard GChiapponi CMollett BAnderson TKEssen SMoreno AEverett HShaw-Saliba KLopes SBrown IHBaker ALHufnagel DEVenkatesh DSimon GChen K-FPekosz AfalseQuantifying the zoonotic risk profile of European influenza A viruses in swine from 2010 to 2020 inclusive.H1 and H3 influenza A viruses (IAVs) circulating in European pigs are markedly distinct from those circulating in other global swine populations. These viruses exhibit significant genetic diversity, further expanded by periodic interspecies transmission of IAVs from humans into pigs, followed by sustained circulation. Several zoonotic IAV infections in humans in Europe have been associated with the 1C lineage of H1 IAVs. Given the predominance of H1 detections in pigs and their zoonotic potential, we quantified antigenic evolution of H1 viruses in European pigs using ferret and pig models and assessed diversity relative to swine IAV vaccine strains. Ferret and swine antisera comparisons revealed no significant differences in antibody responses. Viruses of the 1A.3.3.2 clade exhibited reduc2025-01-01T00:00:00Z2025 Jul2026-03-15T18:18:14.105Z2025-08-13T03:04:27.945ZS-EPMC122884904046457710.1128/jvi.00306-25