In the present study, the tolerability of vaccine composition components in the absence of an antigenic component was evaluated following intranasal and sublingual administration in white outbred laboratory mice. The investigated substances included excipients of the vaccine composition—mannitol (3%, 5%, 7%) and gelatin (0.3%, 0.5%, 0.7%)—as well as phosphate-buffered saline (PBS, 0.01 M, pH 7.2–7.4) used as a buffering medium, and water for injection employed as a technological solvent in the preparation of vaccine candidates. Intact animals served as the control group. The substances were administered sublingually (50 µL) and intranasally (30 µL).

Over a 10-day observation period, local (mucosal) and systemic tolerability of the investigated substances was assessed based on body-weight gain, clinical condition of the animals, and blood biochemical parameters, including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, as well as total bilirubin, glucose, and total protein levels. All tested substances demonstrated good tolerability: body-weight gain remained within physiological limits, local reactions at the mucosal level were absent or minimal, no systemic clinical manifestations were observed, and blood biochemical parameters remained within reference ranges. Based on the overall assessment of the evaluated parameters, mannitol at a concentration of 5% and gelatin at 0.5% were identified as optimal.

The obtained data indicate the safety of the investigated components and technological media and may be applied at the stage of developing manufacturing technology for vector-based anti-brucellosis vaccine candidates based on the influenza virus.

This study presents the results of a comprehensive investigation of the biological properties of the highly pathogenic avian influenza virus isolate A/Cygnus cygnus/Karakol lake/01/2024 (H5N1), obtained during the 2023–2024 outbreak in the Mangystau region of the Republic of Kazakhstan. The pathogenicity of the isolate was evaluated in 6-week-old SPF chickens, along with its reproductive activity in developing chicken embryos. The virus demonstrated high virulence, causing 100% mortality of infected embryos within 48 hours and exhibiting a maximal intravenous pathogenicity index (IVPI = 3.6). These findings confirm that the isolate belongs to the highly pathogenic H5N1 variants.

This study presents the results of evaluating the specificity of primers and probes developed for a multiplex real-time PCR test system designed for the detection of avian influenza and Newcastle disease. To assess specificity, RNA samples from Newcastle disease virus, avian influenza virus type A, and infectious bronchitis virus of chickens were used. As positive controls, plasmid DNAs containing fragments of the M gene (Newcastle disease virus) and NP gene (avian influenza virus) were employed, while deionized water served as a negative control. The optimized amplification program included a reverse transcription step, denaturation, and 45 cycles of real-time PCR with registration of fluorescent signals.

The results demonstrated that the developed primers and probes provided selective detection of the target genomic fragments of viruses without cross-reactions or false-positive signals. Additionally, a comparison with commercial kits PCR-GRIPP-A-FACTOR and PCR-NEWCASTLE-FACTOR confirmed the reliability and reproducibility of the obtained data.

Therefore, the developed test system is characterized by high specificity and can be recommended for practical use in veterinary diagnostics.

The present study evaluated the local and systemic tolerability of vaccine formulation components in the absence of antigen following intranasal and sublingual administration in outbred white laboratory mice. The investigated substances included excipients of the vaccine formulation mannitol and gelatin at various concentrations as well as phosphate-buffered saline and water for injection, which are used as technological components during the development of vaccine candidates. The control group consisted of intact animals.

Tolerability was assessed over a 10-day observation period based on clinical condition, body weight dynamics, and key blood biochemical parameters. All tested substances demonstrated good tolerability: no clinically significant local or systemic reactions were observed, and the evaluated biochemical parameters remained within reference ranges. Based on the overall assessment, mannitol at a concentration of 5% and gelatin at 0.5% were identified as optimal.

The obtained results indicate the safety of the investigated excipients and technological components and confirm their suitability for use at the preclinical stage of development of vector-based anti-brucellosis vaccine candidates utilizing an influenza virus platform.

The study presents the results of microbiological assessment of cleanrooms during the industrial production of foot-and-mouth disease vaccine under aseptic processing conditions. The investigations were conducted in Grade A and B areas during 2024–2025. More than 1,800 samples of air, equipment surfaces, and personnel gowning were analyzed. No microbial contamination was detected in air or on production surfaces. In 1.9% of samples taken from personnel garments and gloves, single microorganisms were identified within acceptable regulatory limits. The obtained data indicate the stability of aseptic conditions and the controlled state of the production environment.

This study evaluated the temporal dynamics of hematological parameters in 2–3-monthold Saanen goats after inoculation with virulent pVapA-positive Rhodococcus equi strains. Hemoglobin (Hb), red blood cells (RBC), white blood cells (WBC), hematocrit (HCT), MCV, MCH, MCHC, and RDW were analyzed over a 0–65-day period in comparison with the control group. Overall, no persistent statistically significant differences were detected between the groups at the main time points. A decrease in Hb was observed only in the VapA-108 group on day 65 compared with the control (p=0.033); however, the small number of animals in each group (n=3) requires cautious interpretation of this result. The wide 95% confidence intervals and high coefficients of variation indicated marked individual variability. The obtained data suggest that, in the goat model, pVapA-positive R. equi strains induced a weak and variable response rather than pronounced and persistent systemic hematological alterations.

The global increase in antibiotic resistance, particularly among pathogens of the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae), highlights the urgent need for alternative antimicrobial approaches. One promising strategy is phage therapy, which involves the use of bacteriophages capable of specifically lysing bacterial cells. The aim of this study was to evaluate the quality parameters of experimental batches of the preparation “Bacteriophage against ESKAPE pathogens,” developed at the Research Institute for Biological Safety Problems LLP, Republic of Kazakhstan. Three experimental batches of the preparation (No. 0011224, No. 0021224, No. 0031224) were examined for appearance, extractable volume, hydrogen ion concentration (pH), sterility, and specific activity against ESKAPE test cultures in accordance with SK-ESKAPE-PR-23 requirements, the State Pharmacopoeia of the Republic of Kazakhstan, and regulatory guidelines of the Eurasian Economic Union for biological medicinal products. The results demonstrated that all batches met the established quality requirements, showing stable physicochemical properties, confirmed sterility, and high specific activity maintained at dilutions up to 10⁻⁷–10⁻¹⁰. These findings confirm the stability, quality, and biological efficacy of the investigated bacteriophage preparation and support its potential for further development and application in the prevention and treatment of infections caused by antibiotic-resistant ESKAPE pathogens.