Construction of influenza B virus vero cell adapted strain by genetic reassortment

Objective To construct influenza B virus Vero cell adapted strain by genetic recombination technology by using the influenza B virus Vero cell adapted strain as the parent strain. Methods The chick embryo and Vero cell were co-infected with influenza virus Vero cell adapted strain B/Malaysia/2506/2004 Va (Bv) and the vaccine strain B/massachusetts/2/2012 (BX-51B) recommended by WHO. The reassortants were screened with the anti-Bv serum. Plaque-purified reassortants were used to screen for Vero cell-adapted influenza B virus strains containing the surface antigen of the epidemic strain. Results A Vero cell-adapted influenza B virus strain was obtained with successive passage in Vero cells. The hemagglutination inhibition test and the one-way immunogold agar diffusion test both showed that the reassortant virus was homologous to NYMC BX-51B, and sequence analysis result showed that the reassortment virus has the same HA and NA gene with the vaccine strain. Conclusion B/Malaysia/2506/2004Va (Bv) can be used as a parent strain to prepare Vero cell vaccine against influenza B virus. Key words: Vero cell; Influenza B virus; Genetic reassortment