Adjuvanticity of compound polysaccharides on chickens against Newcastle disease and avian influenza vaccine.

This study was conducted to evaluate the effects of compound polysaccharides (cPS) on the immune responses via chicken models. First, in screening experiment, a comprehensive analysis for immunomodulatory activity of four cPSs, including Astragalus polysaccharides (APS), Epimedium polysaccharides (EPS), sulfated APS (sAPS) and sulfated EPS (sEPS), was performed in vitro and in vivo. APS-sEPS was picked out having the best effect on lymphocyte proliferation and raising the antibody titers. Therefore, the adjuvanticities of APS-sEPS on Newcastle disease (ND) and avian influenza (AI) vaccine were further validated. Chickens were administrated with ND or AI vaccines containing APS-sEPS of 150, 100 and 50 mg/kg, respectively, taking oil adjuvant vaccine as control. It was observed ND or AI antibody titers and lymphocyte proliferation were enhanced at 100 mg/kg of APS-sEPS. In conclusion, appropriate dose of APS-sEPS may be a safe and efficacious immune stimulator candidate suitable for vaccines.