Abstract
The article provides a comparative assessment of two experimental samples of the seven-component vaccine KOMBOVAС-A, manufactured with adjuvants ISA 61 and ISA 50, in terms of: antigenic activity (in laboratory and naturally susceptible animals); influence on the formation of colostral immunity in calves when vaccinating pregnant cows, as well as effectiveness in livestock farming conditions unfavorable for the main respiratory and intestinal diseases of calves of viral etiology. It was found that the vaccine sample based on the ISA 61 adjuvant had a higher antigenic activity compared to a similar sample based on the ISA 50 adjuvant, inducing a higher level of synthesis of post-vaccination antibodies. The use of the vaccine in conditions of a dysfunctional livestock farm has reduced the morbidity and mortality of calves, while the vaccine sample made on the basis of ISA 61 oil proved to be more effective.