Determination of inactivation kinetics in vaccine candidate local BVD virus strains and immunization studies in experimental animals

Although bovine viral diarrhea virus (BVDV) is common in our country and in the world, protection and control strategies are being developed against the disease. One of the prominent measures in protection control programs is seen as vaccination. In the thesis study, it was aimed to determine the proliferation characteristics, inactivation kinetics of vaccine candidate local BVDV strains and the serological responses of inactive BVDV vaccine formulations prepared with different adjuvants in experimental animals. Optimum MOI values of BVDV TR-21, TR-26 and TR-15 strains were determined as 1, 0,1 and 0,1, respectively. In addition, growth curves of TR-21, TR-26 and TR-15 strains were created and it was determined that they reached the highest titers at 48, 12, and 36 hours, respectively, after virus cultivation. In the inactivation kinetic study using BEI as a chemical, it was determined that the TR-21, TR-26 and TR-15 strains were completely inactivated at the 16th, 10th and 10th hours, respectively. Guinea pigs and mice were immunized with formulations using oil-based (ISA 50 and 206), AlOH3-based and saponin adjuvants. In-house ELISA and neutralization test were applied to determine the humoral immune response developed after vaccination, and it was shown that the data confirmed each other. It was determined that oil-based adjuvant groups worked effectively in the vaccine compared to AlOH3-based adjuvant groups. Although the antibody titers of the F-3 formulation on the 21st and 51st days were high in the oil-based adjuvant groups, it was found to be below the F-4 group on the 81st and 111th days. At the same time, due to the nature of the adjuvant used in the F-4 group (w/o/w), it is thought that it will provide convenience in terms of being more comfortable to use in the vaccine formulation stage. The importance of local strains in vaccines and their effectiveness against homologous and heterologous strains have been demonstrated. Applicable up-to-date data were obtained for the production of inactivated local vaccines in the future.