Effects of Selected Adjuvants on Immunogenicity and Protectivity of Pasteurella multocida Bacterin in Chickens

Document Type: Original Articles

Authors

1 Razi Vaccine and Serum Research Institute

2 shahid chamran university

3 Shahid Chamran University

Abstract

Avian pasteurellosis (fowl cholera) is an important disorder affecting domestic and wild birds all over the world. It can be occurred via strains of capsular type A of Pasteurella multocida, though other capsular types are occasionally incriminated. Present study aimed at investigating the effect of some adjuvants on immunogenicity and protectivity of P. multocida bacterin in chickens compared with an iranian commercial vaccine. Eight weeks old laying chicken pullets were vaccinated through two times with an interval of three weeks. Vaccine immunogenicity testing was done through an in-house indirect ELISA and assessing serum antibody titers at 7, 14 and 21 days after primary and 14 days after secondary immunization. A poultry expert recorded possible side effects. For evaluating vaccines’ protection rate, the chickens were subjected to 2 × Lethal Dose 50% of a virulent P. multocida strain two weeks after secondary immunization. The rate of live and normal animals was regarded as protection rate seven days after the exposure. The findings showed that oil adjuvants Montanide ISA 70 and Montanide ISA 71 contained vaccines (with or without saponin) caused a powerful immune reaction than the aluminum adjuvanted vaccine and commercial vaccine (P < 0.05). A significant protection against challenge was merely induced by the oil adjuvanted vaccines (P < 0.05). Majority of the studied chickens showed inflammation at the injection site (yellow) through the trial. Vaccines made by Montanide ISA 70 and Montanide ISA 71 are novel and effective inactivated vaccines that are able to cause significant protection to fowl cholera disorder.

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