Evaluation of inactivated vaccine against fowl cholera developed from local isolates of Pasteurella multocida in Ethiopia

Abstract

Fowl cholera caused by Pasteurella multocida is among the serious infectious diseases of poultry in Ethiopia. This study was conducted to develop a vaccine from local strains of P. multocida and evaluate its performance. Inactivated vaccine was prepared following the OIE standards in three adjuvant formulations (oil, alum and gel). The performance of the different formulations was evaluated at different dose rates (0.5 and 1 mL) and routes (subcutaneous, SC and interamuscular, IM) in vaccination-challenge experiment in a total of 160 (six weeks old) chicken. The vaccinated groups showed significantly higher (P<0.05) mean antibody titer at day 21 (1365.49±376.97) and day 35 (1707±193.95) post-vaccination compared to the mean value at day 0 (200.01±4.91) and that of the unvaccinated group (196.72±10.51.147). The highest antibody titer obtained was for group vaccinated with 0.5 mL of alum-adjuvanted vaccine given IM (2472.96±603.47). The differences in antibody titer among vaccinated groups with respect to types of adjuvant and dose rates were insignificant. All vaccine formulations provided significant protection with survival rates ranging from 80 to 100% with alum-adjuvanted vaccine given IM being superior both in protective efficacy (100%) and in the absence of clinical signs post-challenge indicating its potential application in the control of fowl cholera. Key words: Cholera, Pasteurella multocida, vaccines, poultry, Ethiopia.