DELIVERY OF PSEUDORABIES VIRUS ENVELOPE ANTIGENS ENCLOSED IN IMMUNOSTIMULATING COMPLEXES (ISCOMS) - ELICITATION OF NEUTRALIZING ANTIBODY AND LYMPHOPROLIFERATIVE RESPONSES IN SWINE AND PROTECTION IN MICE

An experimental subunit vaccine that consisted of pseudorabies virus (PRV) envelope glycoproteins enclosed into immunostimulating complexes (PRV(env)/ISCOM) was constructed, and evaluated in DBA/2 mice and inbred swine of the SLA haplotype de. Two to thr ee weeks after the first vaccine dose, specific anti-PRV antibodies could be demonstrated by ELISA or virus neutralization (VN) assays. Booster PRV(env)/ISCOM vaccinations resulted in rapid and significant increases in antibody titres in both mice and swine. In addition, a week after receiving the third PRV(env)/ISCOM vaccine dose swine peripheral blood mononuclear cells exhibited significant proliferation in response to stimulation with PRV virion antigen. Moreover, two doses of vaccine sufficed to protect mice fully against lethal virus challenge. Therefore, the data presented here support the ISCOM as a viable antigen delivery system for subunit PRV vaccines.