Comparison and efficacy of two different sheep pox vaccines prepared from the Bakirkoy strain against lumpy skin disease in cattle

Purpose: Lumpy skin disease (LSD) is a highly contagious and economically important viral infection of cattle, which leads to financial losses in the livestock industry of affected countries. Vaccination is the most effective control measure to prevent the disease. Heterologous sheep pox (SP) vaccine was used against LSD in Turkey. In this research, it was aimed to adapt SP Bakirkoy vaccine strain attenuated in lamb kidney cells to Madin-Darby bovine kidney (MDBK) cells to provide better protection than commercial SP vaccine in cattle. Materials and Methods: To evaluate safety and efficacy of vaccines, while animals were immunized with 10 doses (10(4.75) 50% tissue culture infectious dose [TCID50]) and 5 doses of SP vaccine (10(4) TCID50) produced in MDBK cells, others were immunized with commercial Penpox-M vaccine (10(3.9) TCID50). Two cattle were kept as unvaccinated. At day 31 post-vaccination, all animals were challenged with the virulent LSD virus. Blood and swab samples were taken on certain days post-inoculation. Logarithmic differences challenge virus titers between vaccinated and unvaccinated animals were calculated. Results: The clinical sign was not observed in animals immunized with 10 doses of SP vaccine. The differences between the animals immunized with SP vaccine and control group was less than log 2.5 and the viremia occurred in immunized animals. The difference in titer was higher than log 2.5 in animals immunized with the Penpox-M, and viremia did not occur. Conclusion: SP vaccine strain propagated in MDBK cells and can be used for immunization to prevent LSD infections. However, SP vaccine strain propagated in MDBK showed poor protection as compared to Penpox-M.