Effects of sulfated polysaccharides and their prescriptions on immune response of ND vaccine in chicken

In order to select the sulfated polysaccharide prescription (sPSP) with the best immunoenhancement, 270 14-day-old chickens were averagely divided into nine groups and vaccinated with ND-IV vaccine. The chickens in seven experimental groups were intramuscularly injected with three sulfated polysaccharides and their four prescriptions (sPSPs). The serum antibody and peripheral lymphocyte proliferation were measured. On day 23 after vaccination, all chickens except for Negative control group were challenged with Newcastle disease virus. The morbidity, mortality and immune protective rate were calculated and their serum antibody titers were determined. The results showed that all sulfated polysaccharides and their prescriptions could obviously or significantly enhance the immune response of ND vaccine in vaccinated chicken and increase the immune protective rate in challenged chicken. sPSP1 possessed the best efficacy, stronger than its components as well, and would be expected as a candidate of new-type immune adjuvant.