ABSTRACT
Murray Valley encephalitis (MVE) is an important mosquito-borne viral disease of Australia that causes annual, sporadic cases and occasional epidemics of potentially fatal encephalitis in man. MVE virus (MVEV) is a spherical, enveloped particle with a positive strand, nonsegmented RNA genome of about 11,000 nucleotides. This chapter discusses properties of the virus, cellular infection, clinical disease and the host immune response to infection. MVEV commonly infects humans without producing apparent illness. MVEV is neurotropic in mice; when small virus doses are injected directly into the brain it grows to high titers and uniformly causes fatal encephalitis. Vaccine efficacy in terms of magnitude and/or quality of the vaccine-elicited immune response is most likely the critical property of the novel Japanese encephalitis virus vaccines for successful vaccination against MVEV. Neutralizing antibodies predominantly target the E protein, and several groups have isolated neutralizing monoclonal antibodies against MVEV and mapped the corresponding epitopes on the E protein.
