Journal of Veterinary Medical Research (Dec 2013)
Comparison of Adjuvant Efficacy of Different Molecular Weights of Chitosan and Aluminum Hydroxide for Inactivated Rabies Vaccine
Abstract
The development of safe, novel adjuvant is necessary to maximize the efficacy of new and/or available vaccines. In this study, three different molecular weights of chitosan (low, medium, high) were evaluated as immunopotentiators/adjuvants of inactivated rabies vaccine in white Norway rats as an experimental model. Two concentrations (1.5% & 3% w/v) of each chitosan type were used in final concentration 5 mg/ml and 10 mg/ml. Results showed that lymphocyte proliferation were significantly elevated (P < 0.05) in all chitosan vaccinated rats compared to aluminum hydroxide gel vaccinated one. All three type of chitosan produced accelerated and enhanced effects on rabies-neutralizing antibody responses in vaccinated groups. Increases in antibody titers together with lymphocytes proliferation responses revealed that chitosan induced both humoral and cell-mediated immune responses. When compared with aluminum hydroxide vaccine adjuvant, chitosan was superior to aluminum hydroxide. The conclusion of these results suggested that chitosan with different MW had a strong potential to increase both cellular and humoral immune responses and that chitosan may be a promising and efficacious adjuvant candidate suitable for inactivated rabies vaccine.
