Development of a recombinant vaccine against Japanese encephalitis.

Japanese encephalitis (JE) is the major form of viral encephalitis in much of the South-East Asia, India, and China. The disease is caused by a mosquito-borne virus known as Japanese encephalitis virus (JEV). The virus spreads in the form of epidemics, although several endemic areas for JEV activity are known. In recent years, JEV has spread to newer geographic locations such as Australia and Pakistan, and thus has become an important emerging virus infection in these areas. A mouse brain-derived, formalin-inactivated vaccine is available for immunization against JE. Because the formalin-inactivated JEV vaccine has limitations in terms of safety, availability, and cost, attempts are being made to develop improved vaccine using the recombinant DNA technology. This article reviews various attempts in this direction and summarizes the latest developments such as the recombinant yellow fever virus- or the plasmid DNA-based JEV vaccine.