This study presents the results of a survey of the safety and protective efficacy of a candidate vector-based vaccine for bovine tuberculosis, using an influenza vector with the NS1 mutation and expressing M. bovis protective antigens ESAT-6 and TB10.4. We vaccinated Balb/c outbred mice two times at 21 days apart. Our experimental design includes mice immunised with the candidate vaccine with or without adjuvant 15% Montanide Gel. The candidate vaccine’s safety was determined by biometric analysis, and protective efficacy was assessed by bacteriological and histological experiments following a virulent M. bovis-8 strain challenge. Our data indicated that the adjuvant-free version of the vaccine ensured complete protection from the M. bovis-8 infection in mice.

Creating an effective and safe vaccine is critical to fighting the coronavirus infection successfully. Several types of COVID-19 vaccines exist, including inactivated, live attenuated, recombinant, synthetic peptide, virus-like particle-based, DNA and mRNA-based, and sub-unit vaccines containing purified immunogenic viral proteins. However, the scale and speed at which COVID-19 is spreading demonstrate a global public demand for an effective prophylaxis that must be supplied more. The developed products promise a bright future for SARS-CoV-2 prevention; however, evidence of safety and immunogenicity is mandatory before any vaccine can be produced. In this paper, we report on the results of our work examining the safety, toxicity, immunizing dose choice, and immunogenicity of QazCoVac-P, a Kazakhstan-made sub-unit vaccine for COVID-19. First, we looked into the product’s safety profile by assessing its pyrogenicity in vaccinated rabbit models and using the LAL (limulus amebocyte lysate) test. We examined the vaccine’s acute and sub-chronic toxicity on BALB/c mice and rats. The vaccine did not cause clinically significant toxicity-related changes or symptoms in our toxicity experiments. Finally, we performed a double immunization of mice, ferrets, Syrian hamsters, and rhesus macaques (Macaca mulatta). We used ELISA to measure antibody titers with the maximum mean geometric titer of antibodies in the animals’ blood sera totaling approximately 8 log2. The results of this and other studies warrant recommending the QazCoVac-P vaccine for clinical trials.

This article presented the results of a study on the impact of physicochemical factors on the biological activity of the SARS-CoV-2 coronavirus isolated from a dog in the Republic of Kazakhstan. The results indicated that storing the virus at a temperature of -70°C led to a decrease in viral activity, similar to the effect observed when stored at room temperature. Storage at +40°C resulted in complete inactivation of the virus. The study on the effect of various concentrations of ionic and non-ionic detergents revealed that exposure to the ionic detergent DOC at concentrations of 0.1% and 0.5% caused a decrease in viral activity, while no change was observed at a concentration of 0.01%. The detergent SDS, at concentrations of 0.01%, 0.1%, and 0.5%, reduced the biological activity of the virus from the initial titer (5.25 lg TCID50/cm³) to 4.00 lg TCID50/cm³. Similarly, the use of non-ionic detergents, Triton X-100 and Tween-20, led to a reduction in viral activity from the initial titer to 4.50 lg TCID50/cm³. The effect of pH in acidic, neutral, and alkaline environments on the biological activity of the virus was also studied. A decrease in viral activity was observed at acidic and alkaline pH levels, whereas a neutral pH environment had no impact on viral activity.

одним из основных критериев биологической безопасности иммунобиологических препаратов является их стерильность. В данной статье представлены результаты оценки двух методов – прямого посева и мембранной фильтрации. А также представлены результаты контроля стерильности инактивированной вакцины против Covid-19 «QazCovid-in®», серии № 0400721, № 0410721, № 0420721. Оценка стерильности испытуемых образцов трех серий вакцины показала, что после инкубации питательная среда оставалась чистой как в образцах прямого посева, так и образцах мембранной фильтрации. Учет и оценка полученных данных исследований проведены в соответствии с Государственной Фармакопеей Республики Казахстан. Для оценки чувствительности двух методов определения стерильности, образцы иммунобиологических препаратов были экспериментально заражены культурами тест-штаммов Staphylococcus aureus, Candida albicans и Clostridium sporogenes. В результате определения стерильности на двух методах, мембранной фильтрации и прямого посева, образцы показали одинаковую чувствительность, при обнаружении дрожжей и анаэробных организмов во всех исследуемых концентрациях тест-штаммов (10, 1, 0,1 КОЕ/мл). А для обнаружения аэробных микроорганизмов метод мембранной фильтрации оказался более чувствительным по сравнению с методом прямого посева, доказательством являются положительные результаты во всех пробах тест-штаммов при мембранной фильтрации (3/3 во всех концентрациях) и отрицательные при постановке метода прямого посева (в концентрациях 1 и 0,1 КОЕ/мл). Таким образом, цель настоящего исследования заключалась в оценке этих двух методов, используемых для определения стерильности иммунобиологических препаратов.

The emergence and spread of coronavirus infections have created a necessity to develop serological methods for assessing population immunity. The enzyme-linked immunosorbent assay (ELISA) remains one of the most accessible and informative approaches for these purposes. The choice of recombinant proteins plays an important role in the sensitivity and specificity of the test system, and in this regard, the creation of a domestic ELISA based on the chimeric SM protein to the SARS-CoV-2 virus is relevant. In this work, a recombinant chimeric SM protein expressed in the E. coli system and purified using metal-affinity chromatography on Ni-NTA agarose was constructed and presented for the first time. An ELISA test system was developed and tested using panels of positive and negative sera, including samples obtained before the COVID-19 pandemic. The obtained sensitivity (90.48%) and specificity (93.65%) indicators with a ROC curve AUC = 0.9623 (OD450 = 0.213) indicate the diagnostic accuracy of the test system. The positive diagnostic ratio (LR+) = 14.25.0 indicates the reliability of a positive result. The domestically developed ELISA test system can be used for serological monitoring and assessment of the immune status of the population.

Hyperimmune sera are a primary component of diagnostic test systems utilising enzyme immunoassay to identify specific antibodies against infectious disease pathogens. During diagnostic assay development, hyperimmune sera function as positive controls and enable the generation of standard curves for quantitative measurement of antibody levels. Furthermore, they can be used to assess the sensitivity and specificity of established test systems and to verify novel diagnostic approaches. The objective of this study was to produce hyperimmune serum against SARS-CoV-2. Purified and concentrated virus, in conjunction with adjuvants such as aluminium hydroxide or AddaS03, was employed to immunise animals. Consequently, specific sera exhibiting activity in ELISA at dilutions of 1:1600- 1:3200 and in the diffusion precipitation reaction (DPR) at 1:8–1:32 were acquired. The research demonstrated that the use of concentrated, pure SARS-CoV-2 for animal immunisation, supplemented with adjuvants, is a viable and efficacious approach for generating highly active antibodies.