Utility of laboratory animals for relative potency evaluation of bovine respiratory viral vaccine | ||
| Benha Veterinary Medical Journal | ||
| Article 40, Volume 31, Issue 2, December 2016, Pages 272-275 PDF (280.27 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/bvmj.2016.31313 | ||
| Authors | ||
| Effat L. El Sayed1; Hanaa A. Mostafa2; Nermeen G. Shafik2 | ||
| 1Veterinary Serum and Vaccine Research Institute, Abbasia, Cairo, Egypt | ||
| 2Central Laboratory for Evaluation of Veterinary Biologics, Abbasia, Cairo, Egypt | ||
| Abstract | ||
| Current potency assay of bovine respiratory viral vaccines is routinely focused on vaccination antibody assay model in susceptiblecattle. Based on the published data among validity of rabbits as a laboratory animals that could be used to evaluate potency of many veterinary vaccines and difficulty in finding seronegative cattle to be used in potency assay of bovine respiratory viral vaccines plus the need to carry batch to batch release potency test in less expensive way, The present study was undertaken to address utility of rabbits for relative potency assay of a combined inactivated vaccine of IBR, BVD,PI3 and BRS viruses in comparison with susceptible calves.Each of two batches of the local vaccine and one imported vaccine was inoculated intramuscularly twice 14 days apart into one group of three seronegative cattle calves using its recommended dose, and one group of five adult bosket rabbits using 2/5 cattle dose of each vaccine.The test vaccine dose dependent immune response assays in calves and rabbits were conducted by inoculation of each of 1/2, 1/4 and 1/8 the full dose of the tested vaccine in one group of each calves and rabbits. Serum samples were collected and measured by serum neutralization test. The tested vaccines were induced mean neutralizing antibody titer averages of (1.05 - 1.5), (1.5 - 1.56), (1.05 - 1.64) and (1.42 - 1.52)log10 in sera of immunized rabbits for BVD, IBR, PI-3 and BRS viruses respectively,and (1.65 - 1.75),(1.5 - 1.8), (1.44 - 1.9) and (1.6 - 1.65)log10 in sera of vaccinated calves for the same viruses respectively by the 3th weekafter boostering; test vaccines seem to be potent in calves and immunogenic in rabbits.Averages of the Relative Potency ( RP ) that determined by dividing each mean virus neutralization antibody titer of log10in sera of the immunized rabbits by that of the vaccinated calves were (0.6 - 0.8), (0.8 - 1.0), (0.5 - 0.8) and (0.8 - 0.9) for each of BVD, IBR, PI3 and BRS viruses respectively by the 3th weekafter boostering. However, the results of the vaccine dose dependent-immune response in both of immunized rabbits and vaccinated calves are proved the sensitivity of rabbits in parallel with calves to the reduced doses of one of the tested vaccines; the reduced doses of the vaccine were induced a considerable regressed antibody titers in serum of immunized rabbits as in vaccinated calves. In conclusion, the present data indicate that the rabbits constitute as useful suggestive laboratory animals for potency evaluation of the bovine combined respiratory inactivated viral vaccines instead of cattle calves | ||
| Keywords | ||
| Rabbits; potency evaluation; viral vaccines | ||
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