Ovine enzootic abortion (OEA): antibody response in vaccinated sheep compared to naturally infected sheep.

摘要

This study was conducted to assess the antibody response in vaccinated sheep by complement fixation test and competitive ELISA. Two vaccines, Ovax Clamidia (Fatro, Italy) and Ovilis Enzovax (Intervet, Netherlands), were administered to the sheep. Four groups of sheep were tested (I, II, III and IV). In group I, unvaccinated control ewes D, E and F were negative for antibodies against Chlamydophila abortus [Chlamydia psittaci] by CFT and cELISA throughout the experimental period. All the 3 ewes (A, B and C) vaccinated with Ovax Clamidia were negative for antibodies against C. abortus up to day 82 when tested with CFT and cELISA. On days 82 and 98, sheep C was positive by cELISA, but negative by CFT. In group II (vaccinated with Ovilis Enzovax), ewe III had an inconclusive titre in the cELISA, but was negative in the CFT, on day 7. Sheep I and II were negative on day 7, but on day 21, all the 3 ewes showed positive antibody titres by both CFT and cELISA. All 4 positive controls in group III tested positive by the cELISA. Sheep 2 and 3 were also positive in the CFT, whereas sheep 1 and 4 were negative. All 4 serum samples (sheep 5, 6, 7 and 8) from group IV (negative control) tested negative by cELISA and CFT. Although the induction of an antibody response by vaccination with Ovax Clamidia was variable, the unequivocal results in both tests following vaccination with Ovilis Enzovax left no doubt about the induction of specific antibodies using this vaccine.