title: Characterization of cross protection of Swine-Origin Influenza Virus (S-OIV) H1N1 and reassortant H5N1 influenza vaccine in BALB/c mice given a single-dose vaccination.
abstract: BACKGROUND
  Influenza virus has antigen drift and antigen shift effect, vaccination with some influenza vaccine might not induce sufficient immunity for host to the threat of other influenza virus strains. S-OIV H1N1 and H5N1 influenza vaccines in single-dose immunization were evaluated in mice for cross protection to the challenge of A/California/7/2009 H1N1 or NIBRG-14 H5N1 virus.
  
  
  RESULTS
  Both H1N1 and H5N1 induced significant homologous IgG, HAI, and microneutralization antibody responses in the mice, while only vaccines plus adjuvant produced significant heterogeneous IgG and HAI antibody responses. Both alum and MPLA adjuvants significantly reduced the S-OIV H1N1 vaccine dose required to elicit protective HAI antibody titers from 0.05 μg to 0.001 μg. Vaccines alone did not protect mice from challenge with heterogeneous influenza virus, while H5N1 vaccine plus alum and MPLA adjuvants did. Mouse body weight loss was also less significant in the presence of adjuvant than in the vaccine without adjuvant. Furthermore, both H1N1 and H5N1 lung viral titers of immunized mice were significantly reduced post challenge with homologous viruses.
  
  
  CONCLUSIONS
  Only in the presence of MPLA adjuvant could the H5N1 vaccine significantly reduce mouse lung viral titers post H1N1 virus challenge, and not vice versa. MPLA adjuvant induced cross protection with a single dose vaccination to the challenge of heterogeneous influenza virus in mice. Lung viral titer seemed to be a better indicator compared to IgG, neutralization antibody, and HAI titer to predict survival of mice infected with influenza virus.
authors.affiliation: Institute of Preventive Medicine, National Defense Medical Center, PO Box 90048-700, San-Hsia, Taiwan.
authors.forename: Hui-Tsu
authors.initials: HT
authors.lastname: Lin
authors.forename: Chuan-Chang
authors.initials: CC
authors.lastname: Chuang
authors.forename: Hsieh-Ling
authors.initials: HL
authors.lastname: Wu
authors.forename: Der-Ming
authors.initials: DM
authors.lastname: Chu
authors.forename: Yeau-Ching
authors.initials: YC
authors.lastname: Wang
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D056738:Cross Protection / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects / Q000472:pathogenicity*; D053124:Influenza A Virus, H5N1 Subtype / Q000187:drug effects / Q000276:immunology / Q000472:pathogenicity*; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology; D007251:Influenza, Human / Q000188:drug therapy* / Q000276:immunology / Q000821:virology*; D051379:Mice; D008807:Mice, Inbred BALB C; D013552:Swine / Q000821:virology; D015164:Vaccines, Inactivated / Q000008:administration & dosage
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007252:Influenza Vaccines; D015164:Vaccines, Inactivated