EN
The aim of the study was to investigate the influence of two components of Rispoval 3 vaccine i.e. PI3V and BRSV administered to calves by the intranasal route on the changes of in selected subpopulations of peripheral blood leukocytes. Eighteen clinically healthy calves were divided into two equal groups. In calves from the experimental group both live attenuated viruses i.e. parainfluenza virus (PI3V) and bovine respiratory syncytial virus (BRSV) were intranasally administered into the animals. Directly before administration, the lyophilised form of the viruses were suspended in 10 ml of the sterile physiological saline. Then each experimental animal was intranasally treated with 2 ml of the suspension, while the control calves received a similar value of placebo, which was a sterile physiological saline. The blood samples were collected at 6, 24, 48, 72, and 168 h after the administration. The following parameters were assayed: the percentage of CD2⁺ (T-lymphocytes), CD4⁺ (T-helper lymphocytes), CD8⁺ (T-suppressor/cytotoxic lymphocytes), and WC4⁺ (B-lymphocytes) cells, and also leukocytes expressing CD11b⁺ (α sub-unit of β2 integrin). The obtained results indicated a statistically-significant (P<0.05) increase in all the examined parameters in the experimental group of animals when compared with the controls. Intranasal PI3V and BRSV administration in calves considerably stimulated both cellular and humoral specific components of immune response in the affected animals. It probably indicates effective protection against infection as a result of applied immunisation.