EVALUATION OF THE EFFECTS OF DIFFERENT ADJUVANTS ON IMMUNOGENICITY AND PROTECTIVITY OF PASTEURELLA MULTOCIDA VACCINE IN CHICKENS

Background and Aim:The aim of the current study was to investigate selected adjuvants on immunogenicity and protectivity of Pasteurella multocida bacterin in chickens in comparison with an Iranian commercial vaccine.Methods:Different groups of 8-week-old laying chicken pullets were immunized with vaccines for two times, 3 weeks apart. Vaccine immunogenicity was assessed by measuring serum antibody titers at days 7, 14 and 21 post-primary and day 14 post-secondary immunization, by an in-house indirect ELISA, and their probable side effects were monitored by a poultry specialist. To evaluate the protectivity of vaccines, the immunized chickens were challenged with 2 × LD50 of a virulent P. multocida strain, 2 weeks post-secondary immunization, and the protection level was expressed as the percentage of live and healthy animals at day 7 post-challenge.Results:The results showed that the vaccines formulated with oil adjuvant Montanide ISA71 (with or without saponin), aluminum adjuvanted vaccine and commercial vaccine induced a strong immune responses as compared to others (P < 0.05). Only the oil adjuvanted vaccines without saponin and the commercial vaccine could induce an acceptable protection against challenge (100%). In most tested chickens, the injection sites were inflamed and had a yellow appearance during the experiment.Conclusion:In general, it seems that ISA70- and ISA71- containing vaccines, as two new and efficient inactivated vaccines, can induce significant protection against fowl cholera disease.

کلیدواژه ها:

Vaccine ، Chicken ، Adjuvants ، Pasteurella multocida