ABSTRACT
To investigate the protection effect of DNA vaccine in mammalian and avian systems, the DNA vaccine was inoculated in both BALB/c mice and SPF chickens immunized with DNA vaccines encoding hemagglutinin (HA) from A/Goose/GuangDong/1/96 (H5N1) virus. The mice and chickens were immunized twice, 3 weeks apart, by electroporation into muscles or intramuscular injection. Two weeks after the second immunization, the mice and chickens were challenged with a lethal dose of homologous virus. The mice and chickens immunized by electroporation obtained completely protection against the virus, and could effectively inhibited viruses to replicating in mouse lung and chicken cloaca. At the same time, these protections were companied by high levels specific antibody to H5N1 AIV, while the blank plasmid controls experience 100 percent mortality following challenge. Furthermore, in the experiment of mice by eletroporation,stronger obviously CTL activity were observed after challenge. Thus, the cellular immune responses of the mice immunized by electroporation were exhibited. These results strongly demonstrate that HA DNA vaccines provide effective protection against influenza virus infection in mammalian and avian, and suggest that electroporation is one of the efficient gene delivery systems for the transfer of influenza DNA vaccine in both humoral immunity and cellular immunity.