A Solution with Ginseng Saponins and Selenium as Vaccine Diluent to Increase Th1/Th2 Immune Responses in Mice

Pseudorabies is an important infectious disease of swine, and immunization using attenuated pseudorabies virus (aPrV) vaccine is a routine practice to control this disease in swine herds. This study was to evaluate a saline solution containing ginseng stem‐leaf saponins (GSLS) and sodium selenite (Se) as a vaccine adjuvant for its enhancement of immune response to aPrV vaccine. The results showed that aPrV vaccine diluted with saline containing GSLS‐Se (aP‐GSe) induced significantly higher immune responses than that of the vaccine diluted with saline alone (aP‐S). The aP‐GSe promoted higher production of gB‐specific IgG, IgG1, and IgG2a, neutralizing antibody titers, secretion of Th1‐type (IFN‐ γ , IL‐2, IL‐12), and Th2‐type (IL‐4, IL‐6, IL‐10) cytokines, and upregulated the T‐bet/GATA‐3 mRNA expression when compared to aP‐S. In addition, cytolytic activity of NK cells, lymphocyte proliferation, and CD4 + /CD8 + ratio was also significantly increased by aP‐GSe. More importantly, aP‐GSe conferred a much higher resistance of mice to a field virulent pseudorabies virus (fPrV) challenge. As the present study was conducted in mice, further study is required to evaluate the aP‐GSe to improve the vaccination against PrV in swine.