Current State of the Development of Next-Generation Vaccines against Ebola Virus Disease

Representative of Ebolavirus gender, Filoviridae family, Ebola virus is an etiological agent of particularly dangerous viral fever, the lethality of which comes up to 88 %. According to the leading specialists and experts in the sphere, vaccination is the most effective and cost-efficient method for the protection from epidemic spread. Objective of the review is to analyze current state of the development of next generation vaccines against Ebola fever. It is established that focus areas of the activities are the construction of vaccines on the basis of alpha-virus replicons, virus-like particles, and the development of DNA-vaccines and vector recombinant vaccines. The paper discusses the most significant achievements in the sphere of obtainment of potent therapies for prophylaxis as regards Ebola fever. To date manufactured, using various approaches, have been the next-generation vaccine preparations, for a number of which high protective capacity is demonstrated in the course of experiments on the nonhuman primates. The most advanced and prospective prototype is the vector recombinant vesicular stomatitis virus-based vaccine

Analysis of the Impact Consequent to the Emergence of Imported Ebola Virus Disease Cases in the Russian Federation

Objective of the study was to forecast the scale of the outbreak that would emerge after arrival of persons infected with Ebola virus into the Russian Federation. Initial data for the prediction were obtained from retrospective analysis of hemorrhagic Ebola fever outbreaks registered within the period of 1976-2014, and the spread of the virus in the Republic of Guinea and Mali in 2014. Delays in the identification of a patient and the lack of compliance with control measures may result in secondary disease in 3-5 persons from among the members of the family and the medical staff. Timely diagnostics and strict observance of safety regulations for treatment of patients with fever of unknown etiology will minimize the number of secondary diseases to a single case or none at all

Forecasting of the After-Effects of A(H7N9) Modelled Outbreak in the Territory of the Russian Federation

Objective of the study is to evaluate economic losses in the consequence of A(H7N9) virus emergence in the territory of the Russian Federation. Materials and methods. Economic damage from induced fatalities has been predicted using DALY index, taking into account the life loss, depending upon the age of the infected persons and associated amount of short-received gross domestic product (GDP). Results and conclusions. Since nowadays there are reported cases of the disease in China, one should expect individual cases of flu among those, arriving in the Russian Federation from this country. Economic loss is forecasted for the outbreak involving infection of two individuals with A(H7N9) virus; the age of the first patient is over 50, and the outcome of his disease will be lethal. Treatment expenses for two patients may come up to 10.9-21.8 thousand rubles, and economic impact from short-received GDP - up to 3900 thousand rubles

Finite size and intrinsic field effect on the polar-active properties of the ferroelectric-semiconductor heterostructures

Using Landau-Ginzburg-Devonshire approach we calculated the equilibrium distributions of electric field, polarization and space charge in the ferroelectric-semiconductor heterostructures containing proper or incipient ferroelectric thin films. The role of the polarization gradient and intrinsic surface energy, interface dipoles and free charges on polarization dynamics are specifically explored. The intrinsic field effects, which originated at the ferroelectric-semiconductor interface, lead to the surface band bending and result into the formation of depletion space-charge layer near the semiconductor surface. During the local polarization reversal (caused by the inhomogeneous electric field induced by the nanosized tip of the Scanning Probe Microscope (SPM) probe) the thickness and charge of the interface layer drastically changes, it particular the sign of the screening carriers is determined by the polarization direction. Obtained analytical solutions could be extended to analyze polarization-mediated electronic transport.Comment: 35 pages, 12 figures, 1 table, 2 appendices, to be submitted to Phys. Rev.

Optimization of Vaccine Virus Accumulation in the Development of Smallpox Drugs Based on Cell Cultures

Objective. Optimization of vaccine virus cultivation in the suspended cell culture BHK-21 for infectious activity increment of virus-containing suspension as the base material for smallpox vaccine preparations. Materials and methods. We used suspended culture line of the cells BHK-21 of 72-hour age and nutrient medium of the MEM type in accordance with the guidelines on preparation in our studies. For challenging of the cells, vaccine virus (strain B-51) was used. The virus was adapted through three consequent passages on horion-allantois shell of developing chicken embryos of commercial dermovaccine series 449а at the premises of the Federal State Budgetary Institution “the 48th Central Research Institute” of the Ministry of Defense of the Russian Federation. Information on its genetic features is absent. Cultivation and precipitation of infected cells BHK-21 was carried out in bioreactor with priming volume of 1 liter at (36.5±0.5) °C and aeration with air mixture with varying content of CO2. Results and conclusions. Gas  massexchange intensity was enhanced alongside simultaneous maintaining of sparing hydrodynamic conditions for mixing suspended cell cultures in bioreactor. Two-fold increase (up to (4.48±0.63)·109 cell/l) in suspended BHK-21 cell culture concentration at the end of reproduction cycle was achieved. Concentration of the vaccine virus was 3–5 times raised, from (8.1±0.3) lg PFU (plaque forming unit)/ml up to the level of infectious activity – (8.8±0.3) lg PFU/ml. Specific multiplicity of cell infection in recalculation per a cell was 1–5 PFU/cell and by virus yield – 20–100 PFU/cell. Enhanced infectious activity of the virus in concentrated suspension of infected BHK-21 cells substantiates the perspectives of the proposed method for improvement of vaccine virus accumulation phase in the development of anti-smallpox preparations based on cell cultures

Environmental, biological and social factors contributing to new rises in COVID-19 morbidity in Russia

Morbidity surveys in certain regions during the COVID-19 pandemic have established that the infection spreads in a wave-like manner characterised with peaks and troughs in incidence. According to the analysis of COVID-19 epidemic development in Russia, surges in COVID-19 infections are mainly driven by seasonal factors, insufficient herd immunity, and emerging SARS-CoV-2 variants with increased transmissibility. The aim of the study was to analyse environmental, biological and social factors contributing to new rises in COVID-19 cases in Russia. The study covers the global epidemiological situation as of mid-2022 and the role of environmental, biological, and social factors in the spread of COVID-19 in the Russian Federation. The results suggest that new highly contagious SARS-CoV-2 variants and seasonality are the principal factors driving new rises in morbidity. The authors assume that the sixth and the seventh COVID-19 waves in Russia will be in line with the best case scenario, which predicts the spread of a SARS-CoV-2 variant with increased transmissibility and reduced virulence

The Current State of Vaccine Development for Specific Prophylactics of Arenaviral Hemorrhagic Fevers

Presently, the Arenavirus genus (Arenaviridae family) includes 26 individual species of viruses. It is divided into two main groups – Old World arenaviruses and New World arenaviruses. The New World arenaviruses comprise four clades: А, B, C, D; pathogenic for humans New World arenaviruses are attributed to clade B. Lassa, Lujo, Machupo, Junin, Guanarito and Sabia viruses are the agents of extremely hazardous hemorrhagic fevers (Lassa hemorrhagic fever, Lujo hemorrhagic fever, Bolivian hemorrhagic fever, Argentinean hemorrhagic fever, Venezuelan hemorrhagic fever, Brazilian hemorrhagic fever, accordingly). These arenaviruses pose a potential threat to national public health due to the possibility of their accidental importation into the territory of the Russian Federation. The vaccination of risk group is the most effective and money-saving means of protection against epidemic spread. Objective of this review is to analyze the specific preparations for arenaviral hemorrhagic fever prevention that are currently under development. Production of live vaccines based on attenuated strains of the agents, the DNA vaccines, vector recombinant vaccines and vaccines on the basis of RNA-replicons is viewed as the main trends in the area. Тhe most important results in the development of effective prophylactic means against arenaviral hemorrhagic fevers are discussed in this paper

Suppression of Octahedral Tilts and Associated Changes of Electronic Properties at Epitaxial Oxide Heterostructure Interfaces

Epitaxial oxide interfaces with broken translational symmetry have emerged as a central paradigm behind the novel behaviors of oxide superlattices. Here, we use scanning transmission electron microscopy to demonstrate a direct, quantitative unit-cell-by-unit-cell mapping of lattice parameters and oxygen octahedral rotations across the BiFeO3-La0.7Sr0.3MnO3 interface to elucidate how the change of crystal symmetry is accommodated. Combined with low-loss electron energy loss spectroscopy imaging, we demonstrate a mesoscopic antiferrodistortive phase transition and elucidate associated changes in electronic properties in a thin layer directly adjacent to the interface