Isolation of anti-Beijing-1 group-specific monoclonal antibody and antigenic analysis of Japanese encephalitis viruses in India.

Based on the reactivities of monoclonal antibodies, we previously reported that 25 Japanese encephalitis (JE) virus strains fell into five antigenic groups: Nakayama, Beijing-1, Kamiyama, 691004 and Muar. In the present study, we produced monoclonal antibodies against the Beijing-1 strain and obtained the Beijing-1 group-specific antibody, designated BEGMA 1. Furthermore, antigenic comparison of the seven JE virus strains isolated in India was performed by using BEGMA 1 and other group-specific antibodies. The results showed that six strains fell into the Kamiyama group to which the currently prevalent strains in Japan belong.