Gamma Interferon Response in Calves to rDNA Vaccine against Bovine Tuberculosis

The recombinant-DNA vaccine against bovine tuberculosis wasevaluated in calves by conducting experiment in three groups of 8calves each, aged approximately 3 months. They were injectedintramuscularly with 1000μg of recombinant-DNA expressingRv3881c protein and a control or unvaccinated group received PBS viathe same route and vector control group received plasmid pjw4303used as vector for rDNA vaccine. The efficacy of the vaccine wastested in a group of calves received from herds with known negativetuberculosis status. Booster vaccinations have been given after 30 daysof initial injection. The cell mediated (Th-1) immune status wasmonitored using the IFN-γ assay and was able to distinguish betweeninfected and healthy calves from an early stage. The immune statusscores of individual animals were generally much higher in therecombinant DNA vaccine than control. The differences betweenrecombinant-DNA to other groups were significant and it is concludedthat under the prevailing conditions the recombinant-DNA vaccine wasable to show higher IFN-γ response in calves against the Bovinetuberculosis.