Antibody responses of heifers vaccinated with reduced doses of Brucella abortus strain 19
DOI:
https://doi.org/10.21423/bovine-vol1983no18p174-178Keywords:
bacterial diseases, brucellosis, Dosage, Immune response, Live vaccinesAbstract
Serum samples were obtained over a six month period from heifers that were either vaccinated with Brucella abortus Strain 19 at one of two reduced doses (109 or 1010 CFU) or not vaccinated. Reactor status was determined by 5 standard tests as well as the hemolysis in gel test (HIGT) and enzyme-linked immunosorbant assay (ELISA). With the standard tests, 50% of the low dose vaccinates and 68% of the higher dose vaccinates were serologically positive 1 month after vaccination. Six months after vaccination, only 8% of the low dose vaccinates and 27% of the higher dose vaccinates were serologically positive by at least one standard test. HIGT failed to detect any cattle as serologic reactors. All cattle were seronegative by ELISA by 5 months after vaccination.