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.

This paper presents a comprehensive analysis and systematization of the key stages of scaling the technological chain of production of cowpox vaccine, with an emphasis on the full-scale adaptation of production processes to strict criteria of good manufacturing practice (GMP). Special attention is paid to the detailed validation of all key stages, including virus cultivation, vaccine formation, lyophilization process and comprehensive quality control of the final product. Validation of key processes was carried out with careful elaboration of virus culture protocols, which included the use of the Nunc Cell Factory, ensuring high stability and reproducibility of the procedure. The introduction of improved methods of microbiological purity control at all stages of production, including regular checks for the presence of microorganisms and monitoring of environmental parameters, contributed to improving the reliability of the production process. Operational standardization was achieved through the integration of real-time systems for data monitoring and analysis, which helped minimize human error and improve production accuracy. As a result, key optimization strategies have been identified and implemented to improve production efficiency, including improving automation processes and digitalizing production lines. The results of the study represent a significant step forward in the development of veterinary vaccinology, providing a reliable basis for future developments and innovations in the field of prevention and treatment of infectious diseases in farm animals. The work highlights the importance of an interdisciplinary approach combining biological, engineering, and management competencies to achieve high standards of vaccine quality and safety. In light of the emerging challenges associated with changes in legislation and the development of new technologies, this work offers a platform for continuing research in the field of biotechnology and vaccine production aimed at adapting to the dynamic conditions of the veterinary industry.

Background: The simultaneous circulation of highly pathogenic avian influenza (HPAI) H5N8 (clade 2.3.4.4b) and virulent Newcastle disease virus (NDV) genotype VII creates a cumulative risk for the poultry industry, rendering monovalent vaccination insufficient. This study aimed to develop and evaluate a combined inactivated vaccine against AIV H5N8 and NDV genotype VII based on local endemic strains. Methods: The vaccine was formulated as a water-in-oil emulsion (30:70) using Montanide™ ISA 78 VG. Evaluation included physicochemical characterization, safety assessment in chickens, immunogenicity evaluation via the hemagglutination inhibition (HI) test, and protective efficacy following challenge with virulent isolates. Results: The formulation demonstrated high stability and complete safety without adverse reactions. By 28 days post-immunization, the vaccine induced a robust, balanced humoral response with antibody titers reaching 9.10 ± 0.23 log₂ against NDV and 9.00 ± 0.26 log₂ against AIV, indicating no antigenic interference. Upon challenge, the vaccinated group exhibited 100% clinical protection and survival, compared to 100% mortality in controls. Furthermore, vaccination significantly reduced viral shedding, limiting horizontal spread. Conclusions: The developed combined inactivated vaccine demonstrates high safety, stability, and protective efficacy. It represents a promising candidate for comprehensive specific prophylaxis in endemic regions, effectively limiting horizontal pathogen transmission and mitigating economic losses in poultry production.