Genetic Stability of A Recombinant Fowlpox Virus Co-expressing H5 HA and N1 NA Gene of Avian Influenza Virus
共表达禽流感病毒HA和NA基因重组禽痘病毒的遗传稳定性

A recombinant fowlpox virus (rFPV) containing H5 HA and N1 NA gene was serially passaged to passage 25 on specific-pathogen-free (SPF) chicken embryo fibroblast monolayer. The HA gene and NA gene from passage 5,15 and 25 were amplified by polymerase chain reaction (PCR) and sequenced. SPF chickens were vaccinated with the recombinant viruses of three passages. The results demonstrated that specific fragments of HA and NA were cloned, identified and sequenced from the three passages, respectively, and there were no change in the amino acid sequences. The virulence and immune efficacy of the recombinant virus was not changed with the passage of the virus. These three passages of recombinant virus could provide complete protection against challenge with homologous HPAIV strain and is genetically stable for at least 25 passages.