title: Efficacy of seasonal pandemic influenza hemagglutinin DNA vaccines delivered by electroporation against a seasonal H1N1 virus challenge in mice.
abstract: Prophylactic DNA vaccines against the influenza virus are promising alternatives to conventional vaccines. In this study, we generated two candidate gene-based influenza vaccines encoding either the seasonal or pandemic hemagglutinin antigen (HA) from the strains A/New Caledonia/20/99 (H1N1) (pV1A5) and A/California/04/2009 (H1N1) (pVEH1), respectively. After verifying antigen expression, the immunogenicity of the vaccines delivered intramuscularly with electroporation was tested in a mouse model. Sera of immunized animals were tested in hemagglutination inhibition assays and by ELISA for the presence of HA-specific antibodies. HA-specific T-cells were also measured in IFN-γ ELISpot assays. The protective efficacy of the candidate influenza vaccines was evaluated by measuring mortality rates and body weight after a challenge with 100 LD(50) of mouse-adapted A/New Caledonia/20/99 (H1N1). Mice immunized with either one of the two vaccines showed significantly higher T cell and humoral immune responses (P<0.05) than the pVAX1 control group. Additionally, the pV1A5 vaccine effectively protected the mice against a lethal homologous mouse-adapted virus challenge with a survival rate of 100% compared with a 40% survival rate in the pVEH1 vaccinated group (P<0.05). Our study indicates that the seasonal influenza DNA vaccine completely protects against the homologous A/New Caledonia/20/99 virus (H1N1), while the pandemic influenza DNA vaccine only partially protects against this virus.
authors.affiliation: Genetic Engineering Laboratory of PLA, Academy of Military Medical Sciences of PLA, Changchun 130062, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Tan
authors.forename: Huijun
authors.initials: H
authors.lastname: Lu
authors.forename: Dan
authors.initials: D
authors.lastname: Zhang
authors.forename: Kaiyan
authors.initials: K
authors.lastname: Wang
authors.forename: Mingyao
authors.initials: M
authors.lastname: Tian
authors.forename: Cunxia
authors.initials: C
authors.lastname: Liu
authors.forename: Yanyu
authors.initials: Y
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.forename: Ningyi
authors.initials: N
authors.lastname: Jin
mesh_terms: D000818:Animals; D002460:Cell Line; D018274:Electroporation; D006801:Humans; D056724:Immunity, Humoral / Q000276:immunology; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000517:prevention & control*; D058873:Pandemics; D012621:Seasons; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D007252:Influenza Vaccines; D019444:Vaccines, DNA