Method of obtaining and storing hyperimmune anthrax serum

Anthrax is a highly dangerous disease of animals and humans caused by the spore-forming bacterium Bacillus anthracis. Currently, the disease is widespread in many countries of the world. Many regions of the Russian Federation are anthrax-endemic. A large number of anthrax treatment, diagnosis and prevention tools are developed using hyperimmune serum. Currently known commercial hyperimmune sera are produced by 2-month long immunization of horses, which is a long and expensive process. This suggests the need to develop faster and cheaper ways to produce anti-anthrax hyperimmune sera; such possible ways became the objective of this study. A live culture of Bacillus anthracis 55-VNIIVViM vaccine strain, used to produce live vaccines against animal anthrax, was used in the experiments. Rabbits were used as animal models. Based on the findings the method of rabbit immunization was selected. The optimal method included intravenous injection of the antigen in increasing amounts according to the following scheme: injection I – 0.5 cm 3; injection II – 1 cm3; injection III – 2 cm3 at a dose of100million mc / animal in 1cm 3, with 4-day interval between injections. This scheme made it possible to produce the serum with a high antibody titer equal to 14 log2. For long-term storage of the serum produced, the freeze-drying modes were optimized, giving 2% residual moisture content of the finished product. The analysis of the freeze-dried serum storage terms showed that the initial activity and physico-chemical properties of the product are maintained for 30 months.