Survival and dispersal of brucella vaccine strain brucella abortus 19 in the body of vaccinated animals

In the general complex of antibrucellosis measures, specific prevention of the disease occupies an important place. The first experiments on vaccination of animals against brucellosis were carried out in the early 20th century. Experiments have shown that even a single subcutaneous vaccination with a live virulent culture 2 months before fertilization in 90% of cases protects animals from subsequent infection and abortion. Of all the brucellosis vaccines used in different countries, the most widespread is the vaccine from the B. abortus 19 strain, which is used to prevent brucellosis in all farm animals. When studying the dispersal and survival of brucella of the vaccine strain in the body of animals vaccinated with different doses of the vaccine, it proceeded similarly, without significant difference (P>0,05). The infection index in heifers vaccinated with a small dose 1 month after vaccination was 60±2, and in heifers vaccinated with a full dose - 74±4. Two months after vaccination, the infection index was 44±16 and 44±4, respectively. 2 months after vaccination, the total number of isolated cultures was 21% less than in the study 1 month after vaccination. According to the total data, 38.5% of cultures were sown from the pharyngeal and prescapular lymph nodes of heifers vaccinated with a small dose 1 month after vaccination, and 20% after 2 months. In heifers vaccinated with a full dose, 28.1% and 26.9%, respectively. Thus, the results of the experiment showed that the dispersibility and survival rate of brucella vaccine strain B. abortus 19 in the body of heifers slightly depends on the dose of the vaccine, which is consistent with the data obtained by us in the experiment on guinea pigs, as well as with the data of other authors.