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

Comparative characteristics of COVID-19 vaccines used for mass immunisation

The pandemic of the new coronavirus (COVID-19) disease that began in December 2019 in China is still having a huge impact on all spheres of human life. The herd immunity, which is the most effective tool for preventing the spread of the disease, is formed in two ways: the passive way (i.e., the formation of a population not susceptible to re-infection due to the natural spread of the disease) and the active way (mass immunisation). High rates of COVID-19 vaccination were achieved thanks to the development and mass production of new vaccines. The selection of the most promising vaccine platforms is one of the key aspects of successful mass immunisation. The aim of the study was to compare the characteristics of COVID-19 vaccines used for mass immunisation. The paper analyses the vaccine technology platforms, efficacy of different types of vaccines based on clinical trial results, safety of vaccines for different population groups, and potential for scaling up vaccine production in order to ensure the necessary vaccination coverage. The vaccines currently used for mass immunisation are: BNT162b2 (Pfizer/BioNTech), mRNA1273 (Moderna), Gam-COVID-Vac (N.F. Gamaleya National Research Center for Epidemiology and Microbiology), Ad26.COV2.S (Johnson & Johnson), ChAdOx1-S (AZD1222) (AstraZeneca), BBIBP-CorV (Sinopharm), CoronaVac (Sinovac Biotech), and NVX-CoV2373 (Novavax). The comparison of the main characteristics of the vaccines demonstrated that the most promising types of vaccines for COVID-19 specific prophylaxis are RNA vaccines and recombinant adenovirus vector-based vaccines

Molecular Mechanisms of Ebola Virus Entry into Permissive Cells

Ebola virus, representative of the Ebolavirus genus, Filoviridae family, causes severe hemorrhagic fever in humans, with lethality rates amounting up to 90 %. The members of Ebolavirus genus infect a broad range of mammalian cells. Recent studies indicate that entry of Ebola virus into cells requires a series of cellular protein interactions and molecular mechanisms, some of which are unique to filoviruses, while others are commonly used by all viral glycoproteins. The cellular factors deployed by filoviruses for their entry into permissive cells are defined incompletely. The aim of this review is to analyze peculiarity of the Ebola virus penetration into permissive cells at molecular level. The Ebola virus entry into cells is initiated by the interaction of viral glycoprotein with one or more receptors on the surface of host-cell. The main host-cell factors, involved in filovirus entry, are: attachment factors (cell lectins and human T-cell mucin 1 (TIM-1)), signaling factors (tyrosinkinase receptors and α5β1-integrin), and endolisosomal host-cell factors (cathepsins B and L and Niemann-Pick C1 protein. The study of the complex set of virus entry events provides potential avenues for the development of antiviral therapies against Ebola fever

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

Diagnostics of Severe Fever with Thrombocytopenia Syndrome – Disease, Caused by Novel Phlebovirus

In 2009, a novel virus, named severe fever with thrombocytopenia syndrome (SFTS) virus, was isolated from a patient in China. The illness caused by this novel virus is characterized by a sudden onset of fever and respiratory or gastrointestinal disorders, followed by progressive thrombocytopenia and leucocytopenia, the case-fatality rate amounting to 6–30 %. Genomic sequencing of the isolated agent indicated that the SFTS virus constituted a new (third) group of Phlebovirus genus, Bunyaviridae family. Presently, different means for specific diagnostics of SFTS (real-time reverse transcription polymerase chain reaction, indirect fluorescent antibodies method, enzyme-linked immune-sorbent assay) are developed. Constructing of diagnostic kits, basic characteristics of methods for determination of causative agent of infection or specific antibodies against it are considered in this review

Comparative analysis of existing platforms for the development of vaccines against dangerous and extremely dangerous viral infections with pandemic potential

The main triggers of new infectious diseases, including those with pandemic potential, are: spontaneous emergence of infectious strains which are more virulent for humans and contribute to transmission of pathogenic microorganisms, environmental changes, social and economic factors, increased contact rates between different regions. A successful pandemic response requires mass immunisation against a specific disease, aimed at the development of herd immunity which is based on the concept of indirect protection of the whole of the population by immunising a part of it. A well-grounded choice of the vaccine platform is central to dealing with this problem. The aim of the study was to compare characteristics of vaccine platforms (attenuated, inactivated, subunit, recombinant vector, DNA, and RNA vaccines) intended for mass immunisation against dangerous and extremely dangerous viral infections with pandemic potential. The study focused on the members of Poxviridae, Orthomyxoviridae and Coronaviridae families as potential pathogens. The vaccine platforms were compared in terms of the following parameters: capability of producing a robust immune response; protective efficacy; time required for vaccine development and testing; ability to produce vaccine in volumes required for mass immunisation; potential obstacles associated with the intended use of the vaccine. It is expected that in the next few decades DNA and RNA vaccine platforms will be most widely used for development of products against dangerous and extremely dangerous viral infections with pandemic potential, regardless of taxonomic groups of pathogens

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

Nodular Dermatitis: Emergence of Novel Poxviral Infection in Russia

Nodular dermatitis, (dermatitis nodularis), is an exotic for the Russian Federation poxviral disease. Some epizootical characteristics of it, problems of laboratory diagnostics, and possible reasons of extension of agent spread areal are discussed in this review. Phylogenetic analysis of P32 gene nucleotide sequences of dermatitis nodularis virus has also been conducted. It is noted that taking into account the economic loss caused by the disease and possibility of its import into non-enzootic regions, it is necessary to use existing effective means of specific prophylacsis extensively. The swift outspread of the disease in the Russian Federation should be considered as the risk factor for biological safety of our country

MOLECULAR-BIOLOGICAL PECULIARITIES OF ARENAVIRUS REPRODUCTION IN SENSITIVE CELLS

The Arenaviridae family consists of a large group of single strand ambisense RNA viruses that are separated phylogenetically, serologically and geographically into Old World and New World viruses. Recent studies indicate that cellular entry of arenaviruses requires a series of cellular protein interaction and molecular mechanisms. The arenaviruses entry into cells is initiated by the interaction of viral glycoprotein with one or more receptors on the surface of host cells. The main host cell factors that are involved in filovirus entry are attachment factors (α-dystroglycan for Old World and human transferrin receptor 1 for New World viruses), endolisosomal host cell factors (cathepsins B and L and Niemann-Pick C1 protein). The review presents the modern knowledge about the role of structural proteins of arenaviruses and some cell factors in pathogenesis of the diseases, caused by arenaviruses

Природные, биологические и социальные факторы, способствующие возникновению новых подъемов заболеваемости COVID-19 в Российской Федерации

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.В ходе пандемии COVID-19 при анализе заболеваемости в определенных регионах установлен волнообразный характер распространения инфекции, включающий периоды подъемов и спадов заболеваемости. Анализ развития эпидемии COVID-19 в Российской Федерации показывает, что основными показателями, способствующими возникновению подъемов заболеваемости, являются сезонный фактор, недостаточный уровень коллективного иммунитета и распространение новых геновариантов вируса SARS-CoV-2, характеризующихся высокой контагиозностью. Цель работы – анализ природных, биологических и социальных факторов, способствующих возникновению новых подъемов заболеваемости COVID-19 в Российской Федерации. Рассмотрена эпидемиологическая ситуация по COVID-19 в мире к середине 2022 г. Проанализирована роль природных, биологических и социальных факторов при распространении COVID-19 в Российской Федерации. Показано, что возникновению новых подъемов заболеваемости в наибольшей степени способствует появление новых высококонтагиозных вариантов вируса SARS-CoV-2 и сезонный фактор. Сделано предположение о том, что шестой и седьмой подъемы заболеваемости COVID-19 в Российской Федерации пройдут по оптимистическому сценарию, который предусматривает распространение высококонтагиозного варианта вируса SARS-CoV-2 со сниженной вирулентностью