The safety and immunogenicity of live attenuated bivalent vaccine against bluetongue in mice and sheep

The results of studying of live bivalent vaccine safety against bluetongue on sheep and white mice and immunogenic activity on sheep are presented in this article. Bluetongue is a non-contagious, viral transmissible infection, transmitted by blood-sucking insects of the genus Culicoides, character-ized by febricity, inflammatory and necrotic lesions of oral cavity especially tongue, digestive tract, epi-thelium of crown and base of skin of hooves and degenerative changes of skeletal muscles. The investigations were made in Zhambylsky territory of the Republic of Kazakhstan. It was demonstrated that sheep after vaccine introduction reacted by small body temperature increasing up to (40.1-40.5) degrees Centigrade for 2-4 days and by indu-ration formation on the place of vaccine injection, which was resolving for 2-3 days. The obtained results showed that vaccine had low reactivity and was safe for sheep. Safety activity of vaccine on white mice used as laboratory models also showed the lack of changes both in general condition of animals and local reaction. Vaccine demonstrated pronounced immunogenic characteristics; the max-imum increase of virus titer neutralizing antibodies was up to 3.66 log2 for 21 days with preservation for up to 90 days noted after introduction of sheep. On 180 days antibodies titer was reduced to 1.6 log2 and was preserved on this level up to 360 days. The formation of complement-fixing antibod-ies in the vaccinated sheep was specified on 7 days with preservation for up to 360 days. The evaluation of clinical signs of disease for challenge showed the difference in disease development for the vaccinated and non-vaccinated animals with the difference in 26 points which gave evidence about high immunogenic activity of the tested vaccine. The provided test showed that vaccine against bluetongue was safe for laboratory mice, sheep and stimulated the formation of virus neutralizing and complement-fixing antibodies in organism of sheep.