Field evaluation of inactivated Corynebacterium ovis vaccine in sheep prepared from a local isolate

Document Type : Original Article


1 Department of Serum and Antigens, Veterinary Serum and Vaccine Research Institute, Abbasia, Cairo, Egypt.

2 Department of Animal Medicine, Faculty of Veterinary Medicine, Benha University, Egypt.

3 Central Laboratory for Evaluation of Veterinary Biologics, Abbassia, Cairo , Egypt.

4 Department of Anaerobic Vaccines, Veterinary Serum and Vaccine Research Institute, Abbasia, Cairo, Egypt.


; "> Corynebacterium pseudotuberculosis vaccine was prepared from a local field
isolate. Vaccination of sheep with 50g PLD toxoid and 10 mg bacterin adjuvanted
with Montanide oil improved the levels of immune responses of sheep. In many
countries, inactivated C. pseudotuberculosis adjuvant vaccines have been used for
prevention and control of caseous lymphadenitis in sheep. However, the efficacy
was variable. The aim of the present study was directed to prepare and evaluate
the potency of an inactivated C. pseudotuberculosis vaccine using Montanide
ISA206. Sheep were vaccinated with 1st dose of 2ml containing 10 mg bacterin and
50g toxoid and Montanide ISA 206 oil adjuvant and boostered with the same
dose 15 days Apart. Evaluation of post vaccinal cellular immune response with
lymphocyte proliferation assay and humoral immune response using ELISA was
carried out. Cell mediated immune response of vaccinated sheep reached its peak
0.445 by 1st week post the second vaccination. The level of humoral immune
response showed optical density of 1.005 by 1st week post the second vaccination.
Challenge test was done in all sheep four weeks after the second dose of
vaccination. Three sheep from vaccinated and three sheep from non-vaccinated
groups were slaughtered and necropsied 150 days post challenge. The results
revealed 75% protection percentage against challenge while unvaccinated
challenged sheep showed 9% protection. Statistical analysis indicated that the
vaccine assessed a significant level of cellular and humoral immunity.


Main Subjects