The Antigenic Activity, Safety and Reactogenicity of Vaccines Created Using the Recombinant Strain <i>Escherichia Coli</i>

Abstract

Introduction. Currently, the incidence of viral infections in animals remains a significant problem for the agribusiness of the country. The development of biological products based on the genetic engineering technologies is one of the most promising areas of vaccine production. Research is needed to develop the efficient vaccines against some complex pathogens. Therefore, the aim of this research is studying the antigenic activity, harmlessness and reactogenicity of the vaccines created on the basis of a highly active recombinant microorganism producing strain synthesizing the protein of the bovine respiratory-syncytial virus.Materials and Methods. To study the antigenic activity of vaccines, 4 groups of clinically healthy guinea pigs were formed, 10 heads per group at the age of 45 days and weighing 350-400 g. without the presence of specific antibodies to the vaccine component viruses. Immunisation with experimental samples was performed two times intramuscularly in the dose of 1.0 ml. with an interval of 21 days, the control group was administered the sterile saline solution. The blood samples of the heart were taken using the vacuum blood collection systems before the start of immunisation and 14 days after repeated immunisation. To determine the titer of specific antibodies in the blood of guinea pigs, the indirect hemagglutination reaction was performed with an appropriate erythrocyte diagnosticum containing the vaccine component viruses. To study the harmlessness of vaccines, 4 groups of clinically healthy white mice weighing 18-20 g., 5 heads per group, were formed. The experimental samples were injected subcutaneously in the dose of 0.2 ml. to the animals of the target groups, the mice of the control group were administered the sterile saline solution. To analyse the harmlessness of vaccines, the method of visual observation of animals was used. To study the reactogenicity of the tested vaccine samples, the groups of 5-6 clinically healthy calves aged 2-3 months weighing 60-70 kg. were formed. They were monitored for 10 days. Microsoft Excel and StatBiom 2720 software were used for computer processing of the obtained results.Results. The results of the study of antigenic activity revealed that all the samples stimulate the production of the specific antibodies in guinea pigs. When assessing the harmlessness and reactogenicity, it was found that immunisation does not have a negative effect on the general condition of animals, does not cause allergic reactions at the injection spot, does not disturb the physiological functions of the body and does not cause the death of animals, thus, the laboratory vaccine samples are harmless, areactogenic and have antigenic activity.Discussion and Conclusion. The conducted research indicates the success of using a recombinant strain of E. coli producer in designing the efficient means of specific prevention of the animal viral infections. These results can be used to create the new biological products that will prevent or reduce the risk of bovine viral infections at the livestock enterprises.