Céline Deblanc, Stéphane Quéguiner, Stéphane Gorin, Gautier Richard, Angélique Moro, Nicolas Barbier, Gérald Le Diguerher, Frédéric Paboeuf, Séverine Hervé, Gaëlle Simon
{"title":"Pathogenicity and escape to pre-existing immunity of a new genotype of swine influenza H1N2 virus that emerged in France in 2020.","authors":"Céline Deblanc, Stéphane Quéguiner, Stéphane Gorin, Gautier Richard, Angélique Moro, Nicolas Barbier, Gérald Le Diguerher, Frédéric Paboeuf, Séverine Hervé, Gaëlle Simon","doi":"10.1186/s13567-024-01319-5","DOIUrl":null,"url":null,"abstract":"<p><p>In 2020, a new genotype of swine H1N2 influenza virus (H1<sub>av</sub>N2-HA 1C.2.4) was identified in France. It rapidly spread within the pig population and supplanted the previously predominant H1<sub>av</sub>N1-HA 1C.2.1 virus. To characterize this new genotype which is genetically and antigenically distant from the other H1<sub>av</sub>Nx viruses detected in France, an experimental study was conducted to compare the outcomes of H1<sub>av</sub>N2 and H1<sub>av</sub>N1 infections in pigs and evaluate the protection conferred by the only inactivated vaccine currently licensed in Europe containing an HA 1C (clade 1C.2.2) antigen. Infection with H1<sub>av</sub>N2 induced stronger clinical signs and earlier shedding than H1<sub>av</sub>N1. The neutralizing antibodies produced following H1<sub>av</sub>N2 infection were unable to neutralize H1<sub>av</sub>N1, and vice versa, whereas the cellular-mediated immunity cross-reacted. Vaccination slightly altered the impact of H1<sub>av</sub>N2 infection at the clinical level, but did not prevent shedding of infectious virus particles. It induced a cellular-mediated immune response towards H1<sub>av</sub>N2, but did not produce neutralizing antibodies against this virus. As in vaccinated animals, animals previously infected by H1<sub>av</sub>N1 developed a cross-reacting cellular immune response but no neutralizing antibodies against H1<sub>av</sub>N2. However, H1<sub>av</sub>N1 pre-infection induced a better protection against the H1<sub>av</sub>N2 infection than vaccination, probably due to higher levels of non-neutralizing antibodies and a mucosal immunity. Altogether, these results showed that the new H1<sub>av</sub>N2 genotype induced a severe respiratory infection and that the actual vaccine was less effective against this H1<sub>av</sub>N2-HA 1C.2.4 than against H1<sub>av</sub>N1-HA 1C.2.1, which may have contributed to the H1<sub>av</sub>N2 epizootic and dissemination in pig farms in France.</p>","PeriodicalId":23658,"journal":{"name":"Veterinary Research","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11110284/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Veterinary Research","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1186/s13567-024-01319-5","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"VETERINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
In 2020, a new genotype of swine H1N2 influenza virus (H1avN2-HA 1C.2.4) was identified in France. It rapidly spread within the pig population and supplanted the previously predominant H1avN1-HA 1C.2.1 virus. To characterize this new genotype which is genetically and antigenically distant from the other H1avNx viruses detected in France, an experimental study was conducted to compare the outcomes of H1avN2 and H1avN1 infections in pigs and evaluate the protection conferred by the only inactivated vaccine currently licensed in Europe containing an HA 1C (clade 1C.2.2) antigen. Infection with H1avN2 induced stronger clinical signs and earlier shedding than H1avN1. The neutralizing antibodies produced following H1avN2 infection were unable to neutralize H1avN1, and vice versa, whereas the cellular-mediated immunity cross-reacted. Vaccination slightly altered the impact of H1avN2 infection at the clinical level, but did not prevent shedding of infectious virus particles. It induced a cellular-mediated immune response towards H1avN2, but did not produce neutralizing antibodies against this virus. As in vaccinated animals, animals previously infected by H1avN1 developed a cross-reacting cellular immune response but no neutralizing antibodies against H1avN2. However, H1avN1 pre-infection induced a better protection against the H1avN2 infection than vaccination, probably due to higher levels of non-neutralizing antibodies and a mucosal immunity. Altogether, these results showed that the new H1avN2 genotype induced a severe respiratory infection and that the actual vaccine was less effective against this H1avN2-HA 1C.2.4 than against H1avN1-HA 1C.2.1, which may have contributed to the H1avN2 epizootic and dissemination in pig farms in France.
期刊介绍:
Veterinary Research is an open access journal that publishes high quality and novel research and review articles focusing on all aspects of infectious diseases and host-pathogen interaction in animals.