Brucellosis remains one of the most widespread zoonotic infections worldwide, causing serious veterinary, medical, and socio-economic consequences. The disease, caused by bacteria of the genus Brucella, affects a wide range of domestic and wild animals as well as humans, with global incidence potentially reaching 1.6–2.1 million new cases annually. The most effective approach to combating brucellosis is specific prevention through vaccination. Therefore, we conducted this review to summarize data from existing studies on modern strategies for brucellosis vaccination, types of vaccine platforms, their efficacy, safety, and applicability in veterinary and human medicine. We searched databases including PubMed, Scopus, and Web of Science to identify relevant scientific articles in English published from 1990 to 2025. The aim of this work is to conduct a systematic analysis of modern brucellosis vaccination strategies in livestock and humans, as well as to evaluate the prospects of new vaccine platforms. The review examines live attenuated, inactivated, subunit, vector, and DNA vaccines, as well as their immunological mechanisms of action, advantages, and limitations of application. This information allows for a better understanding of the mechanisms of protective immunity formation and challenges related to DIVA diagnostics (Differentiating Infected from Vaccinated Animals). The “One Health” concept demonstrated the interconnection between human, animal, and environmental factors, emphasizing the need for an interdisciplinary approach to brucellosis monitoring, prevention, and control. Vector vaccines based on influenza virus (Flu-BA), developed in Kazakhstan, have shown high promise, combining immunogenicity, protective efficacy, and a favorable safety profile. Promising directions remain mRNA vaccines, nanoparticles, CRISPR/Cas9 technologies, and mucosal vaccines.

Background/Objectives: Despite the availability of Newcastle disease (ND) vaccines, outbreaks have continued to occur for more than six decades, with significant economic consequences for the global poultry industry. The variability of the Newcastle disease virus requires constant monitoring, detection of new cases, and studies of the origin of the pathogen. The aim of this study was to develop an inactivated ND vaccine using a topical strain with different adjuvants and to compare them for stability, harmlessness, immunogenicity, and efficacy. Methods: A phylogenetic study of the F-gene of the ND strain isolated in Kazakhstan was conducted. The strain, which was selected to create a vaccine for the prevention of the disease, was revealed to belong to genotype VII class II and uploaded to GenBank (NCBI). Two different adjuvants, Montanide ISA 70 VG and Montanide ISA 78 VG, were used to create the vaccine. Birds were vaccinated intramuscularly. Results: Evaluations of antibody titers in the vaccinated groups during the experiment showed that the vaccines induced adequate levels of antibodies to provide protection against the virulent virus. High antibody titers were observed in the hemagglutination inhibition assay (HAI) in the vaccinated groups as early as 14 days post-vaccination in 100% of birds. The average antibody titer in both vaccinated groups exceeded 7 log2, sufficient to prevent clinical signs. None of the vaccinated birds exhibited clinical signs following control infection, whereas unvaccinated birds developed clinical manifestations within three days post-infection, leading to 100% mortality. Conclusions: The vaccine developed using the epizootic topical strain is stable, harmless, immunogenic, and effective when challenged with a virulent ND virus strain at a dose of 105 EID_50/mL.

This study looks into optimal conditions for cultivating the recombinant strains of subtype H5 influenza virus. The study results in establishing optimal conditions (inoculation dose, incubation temperature, incubation time, and chicken embryos’ age) for growing the influenza virus. This study establishes optimum conditions for cultivating the A/Sichuan/26221/2014(H5N6)-PR8-IDCDC-RG42A and A/gyrfalcon/Washington/41088-6/2014(H5N8)-PR8-IDCDC-RG43A subtype H5 influenza virus recombinant strains in embryonated chicken eggs. Data on culturing influenza virus recombinant strains presented herein indicates that they can be used in developing subtype H5 highly-pathogenic avian influenza vaccines. The results of this research will serve as a basis for developing a new inactivated emulgated vaccine following the process previously used by RIBSP to design its commercial vaccine. These optimum conditions are an infective dose of 10000 EID50/0.2 cm3, an incubation temperature of 36±0.50С, an embryo age of 10 days for cultivating the recombinant strain A/Sichuan/26221/2014(H5N6)-PR8-IDCDC-RG42A. Using these culturing conditions allows a stable production of virus-containing materials with an infectivity level of not less than 8.45±0.24 log EID50/cm3, which is fully consistent with requirements for producing inactivated vaccines for avian influenza. And optimal conditions for growing recombinant strain A/gyrfalcon/Washington/41088-6/2014(H5N8)-PR8-IDCDC-RG43A in 10 days embryonated chicken eggs with the infective dose 100000 EID50 in the incubation temperature 350С. These optimum conditions are helping culturing a stable production of virus-containing materials with an infectivity level of not less than 8.74±0.06 log EID50/cm3, which is fully consistent with requirements for producing inactivated vaccines for recombinant strain A/gyrfalcon/Washington/41088-6/2014(H5N8)-PR8-IDCDC-RG43A. Аn optimum incubation time of 48 hours, and relative air humidity of 55±5% for cultivating both recombinant strains.

Despite the availability of Newcastle disease (ND)vaccines, outbreaks have continued to occur for more than six decades, with huge economic consequences for the global poultry industry. The variability of the Newcastle disease virus requires constant monitoring, detection of new cases and study of the origin of the pathogen. The aim of the study was to develop an inactivated ND vaccine using a topical strain with different adjuvants and to compare them for stability, harmlessness, immunogenicity and efficacy. As a result of the phylogenetic study of the F-gene of the ND strain isolated in Kazakhstan, selected to create a vaccine for the prevention of this disease, it was revealed that this pathogen belongs to the genotype VII class II and was uploaded to GenBank (NCBI). Two different adjuvants were used to create the vaccine – Montanide ISA 70 VG and Montanide ISA 78 VG. The birds were vaccinated intramuscularly. Evaluation of antibody titers in the vaccinated groups during the experiment shows that the vaccines were able to induce adequate levels of antibodies to provide protection against the virulent virus. Vaccination provided high antibody titers in the HAI in the vaccinated groups as early as 14 days after vaccination in 100% of birds. When studying the effectiveness of vaccines, the average antibody titer in both vaccinated groups was above 7 log2, which is more than enough to protect birds from clinical signs. None of the vaccinated birds showed clinical signs after control infection. In groups of unvaccinated birds, clinical manifestations were observed as early as 3 days after infection with increasing severity, and eventually they all died (100% mortality). The vaccine from the epizootic topical strain developed by us is stable, harmless, immunogenic and effective when infected with a virulent strain of the ND virus at a dose of 100,000 EID50/cm³.

Background: Brucellosis remains a significant zoonotic infection affecting approximately 500,000 people worldwide annually, with no licensed human vaccine available. Recombinant influenza virus vectors expressing Brucella spp. antigens represent a promising vaccine platform. However, transitioning from laboratory constructs to clinical candidates requires validation of scalable purification methods compliant with Good Manufacturing Practice (GMP) standards. This study aimed to develop and optimize a pilot-scale purification protocol for these vectors. Methods: Recombinant influenza A viruses (H5N1) expressing Brucella spp. antigens (Omp16, Omp19, L7/L12, Cu-Zn SOD) were propagated in MDCK cell culture. The optimized purification process included: (1) clarification; (2) ultrafiltration/diafiltration (100 kDa MWCO); (3) two-step chromatography (anion-exchange Q-Sepharose^® Fast Flow and multimodal Capto™ Core 700); and (4) sterile filtration. Process validation was performed across three independent pilot-scale batches (20 L each). Results: The purification process demonstrated high reproducibility for all constructs. Final preparations met established quality criteria: infectious titer ≥ 5.2 log₁₀ TCID₅₀/mL, hemagglutination activity 7.33 ± 0.58–8.33 ± 0.58 log₂, total protein content 157–305 μg/mL, residual host cell DNA < 10 ng/dose, and bacterial endotoxin levels ≤ 0.15 IU/mL. The overall recovery of infectious virus was 20–24%, an optimal value for multi-stage bioprocessing. Preservation of the target genetic insert was confirmed in all final preparations by PCR and sequencing. Conclusions: The developed integrated purification protocol yields vectors with high purification efficiency, preserving biological activity and meeting regulatory quality requirements for residual host cell DNA and endotoxins. The technological platform demonstrated versatility, robustness (inter-batch coefficient of variation for yield did not exceed 10–12%), and scalability, establishing a foundation for preclinical and clinical studies of candidate brucellosis vaccines.

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.