title: Protective efficacy of a high-growth reassortant swine H3N2 inactivated vaccine constructed by reverse genetic manipulation.
abstract: Novel reassortant H3N2 swine influenza viruses (SwIV) with the matrix gene from the 2009 H1N1 pandemic virus have been isolated in many countries as well as during outbreaks in multiple states in the United States, indicating that H3N2 SwIV might be a potential threat to public health. Since southern China is the world's largest producer of pigs, efficient vaccines should be developed to prevent pigs from acquiring H3N2 subtype SwIV infections, and thus limit the possibility of SwIV infection at agricultural fairs. In this study, a high-growth reassortant virus (GD/PR8) was generated by plasmid-based reverse genetics and tested as a candidate inactivated vaccine. The protective efficacy of this vaccine was evaluated in mice by challenging them with another H3N2 SwIV isolate [A/Swine/Heilongjiang/1/05 (H3N2) (HLJ/05)]. Prime and booster inoculation with GD/PR8 vaccine yielded high-titer serum hemagglutination inhibiting antibodies and IgG antibodies. Complete protection of mice against H3N2 SwIV was observed, with significantly reduced lung lesion and viral loads in vaccine-inoculated mice relative to mock-vaccinated controls. These results suggest that the GD/PR8 vaccine may serve as a promising candidate for rapid intervention of H3N2 SwIV outbreaks in China.
authors.affiliation: Division of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wen
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Ma
authors.forename: Hai
authors.initials: H
authors.lastname: Yu
authors.forename: Fu-Ru
authors.initials: FR
authors.lastname: Yang
authors.forename: Meng
authors.initials: M
authors.lastname: Huang
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Zhou
authors.forename: Ze-Jun
authors.initials: ZJ
authors.lastname: Li
authors.forename: Guang-Zhi
authors.initials: GZ
authors.lastname: Tong
mesh_terms: D000818:Animals; D005260:Female; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics* / Q000276:immunology; D007252:Influenza Vaccines / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D016865:Reassortant Viruses / Q000235:genetics / Q000276:immunology; D059386:Reverse Genetics / Q000379:methods / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D015164:Vaccines, Inactivated; D014779:Virus Replication
chemical_list: D007252:Influenza Vaccines; D015164:Vaccines, Inactivated
keywords: H3N2 subtype; protective efficacy; reverse genetics; swine influenza virus