Protection of chickens from Newcastle Disease by F gene DNA vaccine combined with trivalent oil-adjuvant inactivated vaccine

Objective:To study the new ways of controling Newcastle Disease.Methods:The immune efficacy of the combined inoculation of trivalent oil-adjuvant inactivated vaccine and pcDNA3-F gene eukaryotic plasmids(DNA vaccine) against NDV were observed.Results:Not only the proliferation response of the T lymphocytes from thymus and the B lymphocytes from bursa in chickens immunized with combined inoculation were significant stronger than those of chickens immunized only with trivalent vaccine during all experiment period, but also the titers of HI antibody of chickens inoculated with both trivalent vaccine and DNA vaccine were significant higher than that of chickens inoculated only with trivalent vaccine. When challenged with field strain at 49 days post-inoculation, the chickens immunized with combined inoculation obtained 100% protection, but chickens immunized only with trivalent vaccine only obtained 86.7% protection.Conclusion:The combination of trivalent oil-adjuvant inactivated vaccine and DNA vaccine could highly enhance the immune response and increase the immunity against NDV.