Studies on Cellular and Humoral Immune Responses of Horses Vaccinated with Equine Herpesvirus-1 Vaccine Using Different Adjuvants

Humoral and cellular immune responses of horses vaccinated with inactivated equine herpesvirus-1 vaccine adjuvanted with Montanide ISA70 were evaluated and compared with immune responses of horses vaccinated with a vaccine adjuvanted with Saponin-rehydragel mixture. The virus was inactivated by binary ethyleneimine (at a final concentration of 0.008 M of BEI within 24 hours at 37°C) and residual virus infectivity was carried out on VERO cells and chorioallantoic membrane of ECE. The vaccines were proved to be safe and potent in both pregnant mice and mares. Challenge was applied to inoculated mice to detect the role of vaccine in reduction of virus reisolation. Cell mediated immune responses in horses by lymphocyte blastogenesis assay revealed that there was an increase in the cytotoxic T-Lymphocytes (CTL) at the 5th day post vaccination and declined at 10th day then begin to increase at 5th day post boostering till 30 days post vaccination. Also the results showed that Saponin-rehydragel adjuvanted vaccine induced a moderately increase in CTL than vaccine adjuvanted by Montanide ISA 70. Assessment of the humoral immune responses by using VN and ELISA assays revealed that the vaccine adjuvanted by montanide ISA 70 induced more immune potentiation with high VN index and ELISA antibody titers than vaccine adjuvanted by Saponin-rehydragel adjuvant.