IMMUNOGENICITY OF EXPERIMENTAL LIVE ATTENUATED JAPANESE ENCEPHALITIS VACCINE VIRUSES AND COMPARISON WITH WILD-TYPE STRAINS USING MONOCLONALAND POLYCLONAL ANTIBODIES

A total of 105 hybridomas secreting anti-Japanese encephalitis (JE) vi rus monoclonal antibodies (mAbs) were generated from six fusions again st four strains of JE virus: wild-type strains SA14 and G8924 and live attenuated vaccines SA14-5-3 and SA14-14-2 (PDK-9). Most of the mAbs (87%) elicited haemagglutination inhibition activity while only a mino rity (24%) elicited neutralization. None of the mAbs prepared against SA14-5-3, parent of SA14-14-2, elicited neutralization while the only mAbs prepared against SA14-14-2 that elicited neutralization recognize d flavivirus cross-reactive epitopes. In comparison, mAbs raised again st wild-type strains showed that a spectrum of epitopes with different specificities, including JE type-specific epitopes, elicited neutrali zing activity. Two mAbs, prepared against SA14-5-3 virus, were found t o be vaccine-specific and five, prepared against strains SA14 and G892 4, were wild-type-specific.