This study investigates the virulence properties and pathogenetic characteristics of the Kazakhstani strain of LSDV (LSDV KZ-Kostanay-2018) in indigenous cattle under controlled conditions. Twelve non-breed cattle were inoculated intradermally and monitored for clinical, pathological, and immunological responses. Clinical signs, including fever, skin nodules, and lymphadenopathy, emerged as early as day 5 post-infection (pi), with peak severity observed between days 11 and 14. Rapid seroconversion was observed, with 100% of animals showing virus-neutralizing antibodies by day 13. Pathological findings revealed extensive necrosis, thrombosis, and edema, with pronounced damage in the spleen, lungs, and lymph nodes. Histological analyses identified widespread destructive changes in the dermis and systemic tissues, consistent with highly aggressive disease progression. Viral genome and replication were confirmed in blood, skin nodules, and lymph nodes, with peak viral loads between days 11 and 14 pi. These results align with findings in Russian cattle infected with the Saratov/2017 strain but demonstrate more rapid symptom onset and severe pathology, suggesting strain-specific virulence. These findings contribute to a deeper understanding of LSDV pathogenesis and underscore the importance of regional adaptations in disease management.

An outbreak of camelpox occurred in the Mangistau region of Kazakhstan in 2019. To control the outbreak of camelpox and to prevent its further spread to other regions, camels were vaccinated using live and inactivated camelpox vaccines produced in Kazakhstan. To evaluate the efficacy of these camelpox vaccines in the field, vaccine trials used 172 camels on camel farms in the Beineu district. Of these, 132 camels were vaccinated using a live attenuated camelpox vaccine and 40 camels were vaccinated using an inactivated vaccine to observe immunogenicity and safety. The live vaccine was inoculated into camels by scarification at a dose of 5 × 10⁴ EID₅₀, and the inactivated vaccine was injected intramuscularly at 5 mL twice, with an interval of 35 days. During the safety evaluation, camels administered either vaccine displayed no clinical signs of illness or any adverse effects. Post-vaccination seroconversion demonstrated that the live attenuated vaccine started to elicit antibody responses in some animals as early as day seven, while, by day 28, 99% of vaccinated camels responded. For camels immunized with the inactivated vaccine, seroconversion began on day 21 at low titers ranging from 1:2 to 1:4. Ninety days post vaccination, 77% of the camels demonstrated an immune response that was up to a titer of 1:16. The antibody response waned six months post vaccination in camels vaccinated with two types of vaccine. Nonetheless, both vaccines were 100% effective at preventing clinical disease in vaccinated camels during the camelpox outbreak. All unvaccinated camels became ill, with manifestations of clinical signs characteristic of camelpox. Following these successful field trials in Kazakhstan, a vaccination program for camels, to control camelpox using the domestically produced live attenuated camelpox vaccine, has started.

Peste des petits ruminants (PPR) is an extremely contagious viral disease that significantly affects the health of small ruminants and the economies of livestock, particularly in areas adjacent to endemic regions. This study focused on assessing the vulnerability of different domestic and wild animal species in Kazakhstan, which includes local sheep and goats, African Cameroon goats, saigas, calves, and ground squirrels, to infection by the PPR virus (PPRV). Experimental infections used a virulent strain of PPRV (Nigeria 76/1), with animals being monitored over a period of 21–28 days to evaluate clinical signs, pathological lesions, and viral dissemination. The manifestation of disease differed across species, breed, and age. In Cameroon, goats and saigas displayed severe illness with a mortality rate of 100% and elevated virus levels in key organs, whereas local sheep and goats presented age-related subacute, abortive, and latent manifestations. Calves exhibited mild, subclinical infections, while ground squirrels showed no susceptibility. Viral shedding was observed in the secretions of infected animals, with transmission occurring through airborne and alimentary pathways. No virus carriage was detected in the animals that had recovered. The investigation emphasizes the notable variations in PPRV pathogenesis and transmission risk among different species, highlighting the necessity for focused surveillance and control strategies to avert incursions in PPR-free areas like Kazakhstan.

Background/Objectives: Equine rhinopneumonia, caused by equine herpesvirus types 1 and 4 (EHV-1 and EHV-4), continues to be a significant health and economic concern in the global equine industry, particularly in Kazakhstan. While vaccines targeting EHV-1 are available, there is currently no licensed monovalent vaccine for EHV-4, and existing formulations offer limited protection against this serotype. This study aimed to develop and evaluate a freeze-dried, live-attenuated EHV-4 vaccine with improved safety, stability, and immunogenicity. Methods: A field isolate of EHV-4 was attenuated through serial passaging in primary lamb testicle (LT-KK49) cell cultures. Viral biomass was concentrated and formulated with various stabilizers before freeze-drying. The most effective stabilizer composition—sucrose, gelatin, and lactalbumin hydrolysate—was selected based on viral titer retention. Safety and immunogenicity were assessed in mice, guinea pigs, rabbits, donkeys, and horses. A guinea pig reproductive challenge model was used to evaluate protective efficacy. Results: The optimized lyophilized vaccine retained infectivity (>6.0 log₁₀ TCID_50/cm³) for at least six months at 4 °C. No adverse clinical signs were observed in any test species. Immunization induced robust neutralizing antibody responses in both small animals and equines. In the guinea pig model, vaccinated females demonstrated 100% pregnancy retention and fetal viability following challenge with a virulent EHV-4 strain. Conclusions: This freeze-dried, live-attenuated EHV-4 vaccine candidate is safe, immunogenic, and thermostable. It offers a promising platform for the targeted prevention of EHV-4 infection, particularly in young horses and in regions with limited cold-chain infrastructure.

Prompt determination of the etiological agent is important in an outbreak of pathogens with pandemic potential, particularly for dangerous infectious diseases. Molecular genetic methods allow for arriving at an accurate diagnosis, employing timely preventive measures, and controlling the spread of the disease-causing agent. In this study, whole-genome sequencing of three SARS-CoV-2 strains was performed using the Sanger method, which provides high accuracy in determining nucleotide sequences and avoids errors associated with multiple DNA amplification. Complete nucleotide sequences of samples, KAZ/Britain/2021, KAZ/B1.1/2021, and KAZ/Delta020/2021 were obtained, with sizes of 29.751 bp, 29.815 bp, and 29.840 bp, respectively. According to the COVID-19 Genome Annotator, 127 mutations were detected in the studied samples compared to the reference strain. The strain KAZ/Britain/2021 contained 3 deletions, 7 synonymous mutations, and 27 non-synonymous mutations, the second strain KAZ/B1.1/2021 contained 1 deletion, 5 synonymous mutations, and 31 non-synonymous mutations, and the third strain KAZ/Delta020/2021 contained 1 deletion, 5 synonymous mutations, and 37 non-synonymous mutations, respectively. The variations C241T, F106F, P314L, and D614G found in the 5′ UTR, ORF1ab, and S regions were common to all three studied samples, respectively. According to PROVEAN data, the loss-of-function mutations identified in strains KAZ/Britain/2021, KAZ/B1.1/2021, and KAZ/Delta020/2021 include 5 mutations (P218L, T716I, W149L, R52I, and Y73C), 2 mutations (S813I and Q992H), and 8 mutations (P77L, L452R, I82T, P45L, V82A, F120L, F120L, and R203M), respectively. Phylogenetic analysis showed that the strains studied (KAZ/Britain/2021, KAZ/B1.1/2021, and KAZ/Delta020/2021) belong to different SARS-CoV-2 lineages, which are closely related to samples from Germany (OU141323.1 and OU365922.1), Mexico (OK432605.1), and again Germany (OV375251.1 and OU375174.1), respectively. The nucleotide sequences of the studied SARS-CoV-2 virus strains were registered in the Genbank database with the accession numbers: ON692539.1, OP684305, and OQ561548.1.

В данном исследовании были разработаны защитные формулы для стабилизации аттенуированного вируса SARS-CoV-2 во время сублимационной сушки и хранения. Была проведена систематическая оценка стабилизирующих сред, при этом формулы, содержащие сахарозу, трегалозу и их смеси с пептоном и гидролизатом лактальбумина, продемонстрировали эффективные защитные эффекты. Эти формулы сохраняли биологическую активность и структурную целостность вируса в различных условиях хранения, в течение как минимум 180 дней при температуре ниже 8°C. Потеря вирусной активности была значительно снижена за счет оптимизации соотношений вирусной суспензии к стабилизирующей среде и внесения изменений в процедуру сублимационной сушки, в частности, за счет сокращения продолжительности последнего этапа сушки. Полученные результаты демонстрируют ценность научно обоснованных стабилизирующих агентов в формуле вакцины, гарантирующих эффективность препарата и продлевающих срок годности в различных режимах хранения. Помимо предоставления полезной информации для создания сопоставимых вакцин, эта работа дает прочную основу для разработки живых аттенуированных вакцин со стабилизаторами против SARS-CoV-2 и других патогенов, поддерживая международные усилия по сокращению инфекционных заболеваний.