National Institute of Virology, 20A Dr. Ambedkar Road, Post Box No: 11, Pune-411001.
*Present address – Associate Professor Microbiology, Rural Medical College Pravara Institute of Medical Sciences (PIMS), Loni 413736, India, E-mail: Ecmc@pmtpims.org
Japanese encephalitis virus (JEV) virus is a mosquito-borne Flavivirus, which often produces epidemics of viral encephalitis in South- East Asia and Western Pacific regions, and recently in Northern Australia also. In India the disease is widespread and many virus strains have been isolated both from JE cases and in mosquitoes (Culex spp.). Twenty-one strains of JEV virus analyzed earlier for the epitopes employing monoclonal antibodies (MAbs) raised against glycoprotein ‘E’ of JE virus, showed 15 strains having complete Hs epitope functional (protective) activity (Group I). Five of the six remaining strains depicted only partial Hs epitope activity (Group II) i.e. 3 Indian strains – G9473, 641686 and 755468;one each of Japanese -yoken and Sri Lankan strain –691004 which were studied for in vivo neutralization and passive protection by the MAbs as well as by active immunization with group II strains against lethal virus challenge in Swiss mice. Group II strains were neutralized to some extent by the Hs (H= H1 positive's, s= virus specific) MAbs and the mice were protected against lethal challenge both by active immunization or by the MAbs transferred passively in mice. Also an important role of NHs epitopes in protection was clearly indicated. These findings wound help in evaluating a better strategy of vaccination, thereby protecting the individuals against infections with the virus showing strain variations.
