Inactivated Bovine Viral Diarrhea Virus Vaccine Trigger Leucopenia and Lymphopenia on Calves

Background: Bovine viral diarrhea virus (BVDV) in cattle is a very common viral infection that causes economic losses. In acute infection fever, leucopenia and thrombocytopenia may be observed. BVDV, an enveloped, single-stranded positive RNA virus, is a member of the genus pestiviruses within the family of flaviviridae. Vaccination and eradication programs should be applied against BVDV in herds with high prevalence of BVDV that includes removal of persistently infected (PI) animals from the herds. The vaccines used against BVDV are either modified live virus (MLV) or inactivated-virus vaccines. These commercially produced vaccines are being tested before introduced to the market, although afterwards some have been withdrawn regardless of preliminary tests. For example in Germany in 2010, inactive vaccines were withdrawn from the market when 80% of the newborn calves from vaccinated cattle were hemophilia. This phenomenon indicates the side effects of vaccine were needed by independent laboratories. For these reason in this study, in a dairy farm in 23 calves were investigated the effect of vaccination on the blood values. Materials, Methods & Results: In this study it were used 23 healthy heifers aged 6-12-months old, held in a dairy farm in Kirikkale. All of the heifers were vaccinated subcutaneously with one vial of commercial PregSure BVD inactive vaccine as recommended by the manufacturer. Whole blood samples collected before one week and three weeks after one dose commercial inactivated BVDV vaccination, blood values analyzed and compared. Before and after one week from vaccination, the blood values of hematocrit, hemoglobin, leucocytes, red blood cell, lymphocyte, neutrofil/granulocyte and mean corpuscular hemoglobin concentration were decreased and this decrease was statistically significant (P <= 0.05). Before and after three weeks from vaccination mean corpuscular hemoglobin concentration increase was significant (P <= 0.05). One and three weeks after vaccination were compared, hematocrit, hemoglobin and red blood cell values were decreased and white blood cell, lymphocyte and neutrofil/granulocyte values increased found significant (P <= 0.05). Divided into three groups against to BVDV antigen and antibodies in the serum of samples could not be found. Discussion: In the present study we compared to effect of inactivated BVDV vaccination on blood values analyzed and compared with kinetics. Before study it was confirmed that all animal did not have BDVD specific antibodies by Porquier ELISA. When Before and after one week from vaccination, the blood values of hematocrit, leucocytes, lymphocyte, and mean corpuscular hemoglobin concentration were decreased and this decrease was statistically significant (P <= 0.05). According to these results we found that a single-dose of vaccination causes a partial leucopenia and lymphopenia. To investigate whether vaccinations suppress immune system in calves, number of Treg cell population might be more detail observed after vaccination. As a result, though one dose of inactive BVDV vaccine cause lymphopenia and leucopenia it was unable to achieve high titers of antibodies. However veterinarian and animal owner prefer to perform widespread usage of one dose inactive vaccination in Turkey in order to cheaper than multiple dose vaccination.