Development of prepared H5N1 influenza vaccine strain in Vero cells

The aim was to generate an attenuated and high-yielding H5N1 HPAI virus candidate vaccine from African green monkey kidney(Vero) cells by reverse genetics and to analyze its phenotype characters.The NS gene of A/Puerto Rico/8/34(H1N1) (PR8) was modified with the aim of Vero-adapting,and then synthesized to construct plasmid pHW2000;hemagglutinin(HA) and neuramindase(NA) genes of A/Anhui/01/2005(H5N1) amplified by RT-PCR were cloned into the plasmid pHW2000 for constructing pHW2000-HA and pHW2000-NA.The three plasmids above were cotransfected into Vero cell with other 5 plasmids from PR8 virus recovery system in order to generate the virus.The reassortant H5N1 influenza virus vaccine candidate strain contained the HA antigen phenotype of A/Anhui/01/2005(H5N1) was propagated in Vero cell in a highly-adapted manner.The growth trend of the reassortant virus in Vero cells was significantly improved in comparison to those of viruses rescued with PR8 recovery system.The reassortant H5N1 influenza virus with high adaptability could replicate in Vero cells.And the successfully recovery of H5N1 influenza virus vaccine strain paved the way for large scale produce of influenza vaccine in Vero cells which will benefit influenza epidemic preventing.