title: [Immune Protection against H9N2 Provided by H1N1 Pre-infection in Pigs].
abstract: To explore the impact of the history of infection by the influenza A virus subtype H1N1 on secondary infection by the influenza A virus subtype H9N2, pigs non-infected and pre-infected with H1N1 were inoculated with H9N2 in parallel to compare nasal shedding and seroconversion patterns. Unlike pigs without a background of H1N1 infection, nasal shedding was not detected in pigs pre-infected with H1N1. Both groups generated antibodies against H9N2. However, levels of H1N1 antibodies in pigs pre-infected with H1N1 increased quickly and dramatically after challenge with H9N2. Cross-reaction was not observed between H1N1 antibodies and H9N2 viruses. These findings suggest that circulation of the H1N1 virus might be a barrier to the introduction and transmission of the avian H9N2 virus, thereby delaying its adaptation in pigs.
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.forename: Maocai
authors.initials: M
authors.lastname: Wu
authors.forename: Wenshan
authors.initials: W
authors.lastname: Hong
authors.forename: Zuoyi
authors.initials: Z
authors.lastname: Zheng
authors.forename: Rirong
authors.initials: R
authors.lastname: Chen
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D003429:Cross Reactions; D007106:Immune Sera / Q000276:immunology; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology* / Q000502:physiology*; D053127:Influenza A Virus, H9N2 Subtype / Q000276:immunology*; D009976:Orthomyxoviridae Infections / Q000097:blood / Q000276:immunology*; D013045:Species Specificity; D013552:Swine / Q000276:immunology* / Q000821:virology*
chemical_list: D000914:Antibodies, Viral; D007106:Immune Sera