Adult bovine vaccination against brucellosis by subcutaneous route with reduced doses of Brucella abortus B19

Viana, F.C.; Silva, J.A.D.; Contreras, R.L.; Magalhaes, J.E.P.

Arquivo Brasileiro de Medicina Veterinaria e Zootecnia 38(3): 331-342


In view of the failure of controlling Brucellosis in a chronically injected bovine herd by traditional methods, the adult females were vaccinated, subcutaneously, with reduced doses (3 .times. 10) of Brucella abortus (B19). Two groups wree composed, i.e., Group I.sbd.23 affected animals or suspected 50 before vaccination and Group II.sbd.5 positive reagent animals (non-vaccinated). The animals were submitted to the following serologic tests: Plate Agglutination Test (PAT), 2-Mercaptoethanol (2-ME), Card Test (CT) and the Ring-Test Dilution method (RT). All the negative animals of Group I reacted to PAT (titles 1:50 to 1:800), 30 days post-vaccination and most of them reacted to the other tests. After 5 months; none of the animals presented titles superior than 1:50 to SAT, all were negative to 2-ME and RT, whereas 91.6% were negative to CT. These results did not change after 12 months post-vaccination. As to the suspected cows, higher and more persistent titles were generally observed through different tests. Hence, at the 5th month post-vaccination, 57.1% reacted to PAT (.gtoreq. 1:100), 71.1% to CT, 50.0% to 2-ME and 40.0% to RT (1:1 to 1:8). After 12 months post-vaccination, 16.6% reacted to PAT (.gtoreq. 1:100) and 50% to CT. In Group II (affected cows), titles to PAT fluctuated during an observation period of 4 months. The 2-ME presented titles inferior than those observed through PAT, while CT remained positive during this period. In Group II, RT was done with samples collected from each quarter of the mammary gland and the results showed that title variations among the quarters of one and the same animal. Furthermore, the titles of the animals of Group II were higher than those observed in vaccinated animals of Group I. After 30 months, the disease was controlled through vaccination and other preventive sanitary measures.