Protection of Chickens from Egg Drop Syndrome by Hexon Gene DNA Vaccine Combined with Oil-adjuvant Inactivated Vaccine

The immune efficacy of the combined inoculation of oil-adjuvant inactivated vaccine and pcDNA3-hexon gene eukaryotic expression plasmids (DNA vaccine) against egg drop syndrome virus(EDSV) was observed.The results showed that the proliferation response of the T lymphocytes from thymus and the B lymphocytes from bursa in chickens immunized with combined inoculation were strong than those of chickens immunized only with inactivated vaccine during all experiment period(P0.05 or P0.01,except the B lymphocytes from bursa in two group chickens on 7th day post-inoculation),especially the proliferation response of the T lymphocytes were all significantlt strong than those of chickens immunized only with inactivated vaccine after 14 day inoculation(P0.01).Meanwhile,the titers of HI antibody of chickens inoculated with both inactivated vaccine and DNA vaccine were higher than that of chickens inoculated only with inactivated vaccine during all experiment period,the difference of which was significant during 35-49d post-immunization.It can be concluded that the combining use of oil-adjuvant inactivated vaccine and DNA vaccine could enhance highly the immune response and increase the immunity against EDSV.