[Recombinant fowlpox virus coexpressing HA and NA gene from subtype H5N1 of avian influenza virus and its protective efficacy].

The hemagglutinin (HA) and neuraminidase(NA)gene from subtype H5N1 avian influenza virus were directly inserted into the transferring vector pllS, resulting in the recombinant transferring vector p11SH5ANA. Then p11SH5ANA was transfected into the chicken embryo fibroblasts (CEF), which was pre-infected with wild type fowlpox virus, to generate the recombinant fowlpox virus coexpressing H5A and NA (rFPV-11SH5ANA). By selection of blue plaques on the CEF, rFPV-11SH5ANA was obtained and purified. Experiments on SPF chickens demonstrated that the HI antibody titers in chickens vaccinated with HA-NA coexpressed vaccine was higher than those with HA expressed monovalent vaccines, and all chickens receiving either rFPV-11SH5ANA or rFPV-11SH5A were completely protected from the virulent AIV(H5N1) challenge, while those receiving wt-FPV experienced 100% mortality. The results showed that the rFPV-11SH5ANA was a safe and highly efficient gene engineering vaccine candidate for preventing HPAI.