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.

Introduction. This article presents the results of isolation of camel smallpox virus (Poxviridae: Orthopoxvirus: Camelpox virus, CMLPV) and study of its reproductive properties on sensitive biological systems.Material and methods. The epizootic strain M-96 of the virus as well as its attenuated variants KM-40 and KM-70 obtained by sequential passivation were used in the study. Isolation of the pathogen from suspension of biopsy specimens was performed on cell culture and in embryonated chicken eggs (ECEs). All experiments were performed with the number of replications ensuring obtaining reliable results.Results. The CMLPV was isolated from the crusts and pox papules of the skin taken from sick camels (Camelus bactrianus) during an outbreak in various districts of the Mangistau region at the end of 2019. The signs of pathogen reproduction on chorio-allantoic membrane (CAM) were observed from 3 passages. The obtained virus caused formation of pathological changes on the CAM in the form of elevated dot or solid white formations separated from the surrounding tissue, with hemorrhagic foci in the center. The reproductive properties of the isolate on sensitive biological systems were determined in comparison with the epizootic CMLPV strain M-96, isolated earlier in the territory of Kazakhstan during the outbreak 23–24 years ago, as well as its attenuated variants. The isolated virus was given the conventional name M-2020.Discussion. When studied in two sensitive cultivation systems (cell culture and ECEs), strain M-96 and its attenuated variants KM-40, KM-70, which were used in the experiments as a control, demonstrated high infectious activity with titer 4.75-6.75 lg TCID50/cm3, while for the examined isolate M-2020 of CMLPV had the significantly lower values (3.00-4.75 lg TCID50/cm3, p 0,05).

The article presents the results of the commission testing of the physicochemical and biological properties of the experimental series of the inactivated emulsified monovalent vaccine against bluetongue in animals at the National Reference Center for Veterinary of the Committee for Veterinary Control and Supervision of the Ministry of Agriculture of the Republic of Kazakhstan (CVCS MA RK). General virological and immunological research methods laid down in the regulatory and technical documentation (RTD) of the vaccine were used to conduct the study. The results of the commission studies showed that the vaccine is sterile with respect to foreign microflora, a harmless and immunogenic drug for sheep. On the 21st day after the administration of the vaccine, antibodies are detected in the animals in ELISA, the optical density of the serum of vaccinated animals ranges from 13% to 27%. According to the results of the commission testing, the vaccine meets the requirements laid down in the RTD of the drug. A registration certificate has been received for the drug. It is recommended to use the vaccine on a large scale in sheep and cattle farms, in private farmsteads for specific prevention of bluetongue. In addition, this article presents the results of determining the presence of cross-immunity in sheep infected with various serotypes of the bluetongue virus available at the Institute.

Background/Objectives: Mpox (formerly monkeypox) is a re-emerging global health threat. While current vaccines are injectable, oral vaccination offers a painless alternative, though the harsh gastrointestinal (GI) environment challenges live viral vaccines. This study evaluated the stability of orthopoxviruses under simulated GI conditions to assess the physicochemical feasibility of oral mpox immunization. Methods: Attenuated and virulent strains of vaccinia, cowpox, and camelpox viruses were exposed to simulated gastric (pH 1.0–2.0 and 3.0–4.0 with pepsin) and intestinal (pH 7.0–7.5) conditions at 37 °C for 180 min. Viral titers were determined via cell culture assays. The physicochemical protective efficacy of enteric-coated capsules was evaluated using standard dissolution testing parameters. Results: All orthopoxviruses were rapidly inactivated under highly acidic fasting conditions (pH 1.0–2.0). However, they exhibited high stability at pH 3.0–4.0 and 7.0–7.5, retaining approximately 20–30% of their initial infectivity after 180 min. Enteric-coated capsules successfully maintained shell integrity in simulated gastric fluids for over 3 h and dissolved completely under intestinal conditions within ~130 min, aligning with small intestine transit times. Conclusions: Orthopoxviruses possess sufficient intestinal stability to support the physicochemical feasibility of oral immunization, provided they are protected from gastric acidity. Enteric-coated capsules represent a highly suitable delivery system for the intestinal release of live orthopoxvirus-based candidates, warranting further in vivo preclinical evaluation.

Cowpox virus, belonging to the genus Orthopoxvirus , is widely used as a model for studying orthopoxvirus infections. Despite the availability of data on the susceptibility of different animal species, its assessment under standardized experimental conditions remains limited. The aim of this study was to assess the susceptibility of laboratory animals to cowpox virus and to substantiate the selection of an optimal experimental model. The epizootic strain “COWPOX-CAM” of cowpox virus was used in this study. White mice, guinea pigs, and rabbits were employed as experimental models and infected via the intradermal route. Clinical observations were performed, and the course of the infectious process and the development of pathological changes were evaluated. In guinea pigs, the infection was mild and not associated with mortality. In white mice, the clinical manifestations of infection were mild and were not accompanied by the development of characteristic skin lesions. In rabbits, a pronounced clinical course was observed, including both local and systemic manifestations of infection. The results obtained indicate that rabbits demonstrate the highest susceptibility to cowpox virus and can be considered the most appropriate experimental model for studying the pathogenesis of infection and evaluating the efficacy of vaccines and therapeutic agents.

The article presents a review of modern experimental models used for the study of orthopoxvirus infections. The biological characteristics and pathogenesis of orthopoxviruses are discussed, including mechanisms of replication, immune evasion, and interspecies transmission. Particular attention is paid to the relevance of these studies in connection with the increasing incidence of zoonotic infections caused by monkeypox virus, camelpox virus, cowpox virus, and other representatives of the genus Orthopoxvirus. An analysis of current in vitro and in vivo models used to investigate viral pathogenesis, replication, evaluation of antiviral drugs, and vaccine development is provided. The cultural properties of various orthopoxviruses in Vero, RK-13, CV-1, HaCaT, and other cell lines are described. The advantages and limitations of models involving primates, mice, rabbits, prairie dogs, and alternative reservoir species are considered. It is shown that the combined use of in vitro and in vivo systems represents the most effective approach for studying orthopoxvirus infections, developing vaccines and antiviral agents, and assessing potential epidemiological risks.