A joint research group between the University of Tokyo and Wisconsin University in the United States has succeeded in developing influenza B virus, which has a high proliferative capacity in cultured cells.It will be possible to quickly supply highly effective vaccines.
Current seasonal influenza vaccines are made from viruses that have been increased using fertilized chicken eggs (developed chicken eggs).Mutations in hemagglutinin (HA), the main antigen of the virus, during the growth process are said to significantly reduce the effectiveness of the vaccine.If a vaccine is produced using cultured cells in which such antigenic variation is unlikely to occur, the effectiveness is maintained, but the low proliferative ability of the seasonal influenza virus in the cultured cells has been a major problem.
This time, using the "reverse genetics method" developed by the research group (1999), a mutant population (mutant virus library) consisting of various influenza B virus strains was artificially created.After that, influenza B virus strains with high proliferative ability in cultured cells were selected from the mutant virus library.Next, a virus strain containing the main antigen of the virus that is prevalent in the field was prepared using this influenza B virus hyperproliferation strain as a mother, and its proliferation ability was analyzed.As a result, it was found that this virus strain proliferates efficiently in cultured cells that are often used in the production of cell culture vaccines.
Currently, vaccine manufacturers are preparing for the practical application of cell culture vaccines, but due to the low ability of the virus to multiply, they have not been able to secure a sufficient supply of vaccines.The results of this research will enable the rapid production and supply of cell culture vaccines, which are expected to be more effective than conventional chicken egg vaccines.
