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

Development of the Immuno-Enzyme Test-System for the Detection of <i>Legionella pheumophila</i>, Serogroup I

Developed is the highly sensitive and specific immuno-enzyme test-system, which is perspective for the detection of L. pneumophilia, serogroup 1. Isolated are the three hybrid cell lines that secrete monoclonal antibodies to specific epitopes of L. pneumophilia, serogroup 1 lipopolysaccharide antigen. Hyper immune rabbit sera, characterized by highly specific activity and specificity, are obtained using lipopolysaccharide antigen

Immunogenicity evaluation of Gam-COVID-Vac (Sputnik V)

In November 2020, the Armed Forces of the Russian Federation began mass immunisation of the personnel with Gam-COVID-Vac (Sputnik V), the first Russia vaccine against the new coronavirus infection (COVID-19). Thus, it became necessary to assess post-vaccination antibody levels and the duration and intensity of humoral immunity to COVID-19.The aim of the study was to investigate the immunogenicity and efficacy of Gam-COVID-Vac in military medical staff after vaccination.Materials and methods: the authors determined the presence of specific antibodies in the serum of individuals immunised with Gam-COVID-Vac (477 volunteers) and COVID-19 convalescents (73 patients), using virus neutralisation (VN), enzyme-linked immunosorbent assay (ELISA) with reagent kits by several manufacturers, and immunoblotting. The results of the study were evaluated using analysis of variance.Results: VN detected virus neutralising antibodies in 90.7% of vaccinated subjects; ELISA, in 95.4%. Both VN and ELISA showed lower antibody levels in the vaccinated over 50 years of age. ELISA demonstrated a significantly higher concentration of anti-SARS-CoV-2 spike IgG in the Gam-COVID-Vac group than in the COVID-19 convalescent group. The correlation between antibody detection results by VN and ELISA was the strongest when the authors used their experimental reagent kit for quantitative detection of virus neutralising antibodies by competitive ELISA with the recombinant human ACE2 receptor. Having analysed the time course of neutralising antibody titres, the authors noted a significant, more than two-fold decrease in geometric means of the titres three months after administration of the second vaccine component.Conclusions: the subjects vaccinated with Gam-COVID-Vac gain effective humoral immunity to COVID-19. The decrease in titres indicates the need for revaccination in 6 months

EPIDEMIOLOGICAL SITUATION ON AND PROBLEMS OF IDENTIFICATION OF RABIES VIRUS IN HUMANS IN THE TERRITORY OF THE RUSSIAN FEDERATION DURING THE PERIOD OF 2002–2015

The article presents the results of bioassays investigation by the specialists of the Center for Special Laboratory Diagnostics of Particularly Dangerous and Exotic Infectious Diseases, isolated during 2002–2015, obtained from deceased people suspected for rabies virus infection. Outlined are the main challenges of working with the received samples of biological material from dead people and ways of handling these issues. Put forward are the pressing problems of epizootic and epidemiological bias that require comprehensive solutions on the part of healthcare authorities and the veterinary service of the Russian Federation. Given are the results of the laboratory-diagnostic activities of the Center for Special Laboratory Diagnostics of Particularly Dangerous and Exotic Infectious Diseases, which indicate that the applied methods of isolation and identification of the rabies pathogen allow for efficient and in-time diagnosis of the disease

The Flow Cytometry Study of Cellular Immunity in Rhesus Monkeys after Experimental Infection with SARS CoV 2 Virus

Cellular immunity plays an important role in the pathogenesis and formation of protective immune defense against the SARS‑CoV‑2 virus.The aim of the work was to study the cellular immunity of rhesus monkeys applying flow cytometry after experimental infection with the SARS‑CoV‑2 virus.Materials and methods. Male rhesus monkeys were intranasally inoculated with the SARS‑CoV‑2 virus, Isolate B strain and hCoV-19/Russia/SP48-1226/2020 strain (abbreviated name U-2), at a dose of 5.0 lg PFU. Using flow cytometry, the levels of 21 populations/subpopulations of mononuclear cells in the peripheral blood of animals were determined before experimental infection with the pathogen and on day 14 after infection. SARS‑CoV‑2 coronavirus RNA was assessed using real-time polymerase chain reaction. Determination of the titer of virus-neutralizing antibodies to the SARS‑CoV‑2 virus in the blood sera of animals was conducted through neutralization test evaluating the ability to suppress negative colonies.Results and discussion. Infection with Isolate B strain culture has led to an increase in the relative content of total T-lymphocytes (p˂0.2), cytotoxic T-lymphocytes (p˂0.1), as well as monocytes expressing the early activation marker CD25 (p˂0.2). The decrease in levels has been observed for total B-lymphocytes (p˂0.2) and T-helper cells (p˂0.1). Infection with the U-2 strain culture revealed an increase in the relative content of monocytes expressing the early activation marker CD25 (p˂0.2). Thus, for the first time in the Russian Federation, flow cytometry was used to study the cellular immunity of rhesus monkeys before and after experimental infection with the SARS‑CoV‑2 virus. The obtained information can be used for studying the pathogenesis of SARS‑CoV‑2 infection, course, and outcome of the disease, and developing strategies for vaccination and treatment

Изучение иммуногенности вакцины Гам-КОВИД-Вак

In November 2020, the Armed Forces of the Russian Federation began mass immunisation of the personnel with Gam-COVID-Vac (Sputnik V), the first Russia vaccine against the new coronavirus infection (COVID-19). Thus, it became necessary to assess post-vaccination antibody levels and the duration and intensity of humoral immunity to COVID-19.The aim of the study was to investigate the immunogenicity and efficacy of Gam-COVID-Vac in military medical staff after vaccination.Materials and methods: the authors determined the presence of specific antibodies in the serum of individuals immunised with Gam-COVID-Vac (477 volunteers) and COVID-19 convalescents (73 patients), using virus neutralisation (VN), enzyme-linked immunosorbent assay (ELISA) with reagent kits by several manufacturers, and immunoblotting. The results of the study were evaluated using analysis of variance.Results: VN detected virus neutralising antibodies in 90.7% of vaccinated subjects; ELISA, in 95.4%. Both VN and ELISA showed lower antibody levels in the vaccinated over 50 years of age. ELISA demonstrated a significantly higher concentration of anti-SARS-CoV-2 spike IgG in the Gam-COVID-Vac group than in the COVID-19 convalescent group. The correlation between antibody detection results by VN and ELISA was the strongest when the authors used their experimental reagent kit for quantitative detection of virus neutralising antibodies by competitive ELISA with the recombinant human ACE2 receptor. Having analysed the time course of neutralising antibody titres, the authors noted a significant, more than two-fold decrease in geometric means of the titres three months after administration of the second vaccine component.Conclusions: the subjects vaccinated with Gam-COVID-Vac gain effective humoral immunity to COVID-19. The decrease in titres indicates the need for revaccination in 6 months.В начале массовой иммунизации личного состава Вооруженных Сил Российской Федерации в ноябре 2020 г. первой в России вакциной Гам-КОВИД-Вак против новой коронавирусной инфекции COVID-19 необходимо было оценить уровень антител у вакцинированных лиц, длительность и напряженность гуморального иммунитета против COVID-19.Цель работы: изучение иммуногенной эффективности вакцины Гам-КОВИД-Вак у сотрудников военных лечебных учреждений после вакцинации.Материалы и методы: наличие специфических антител в сыворотке крови лиц, иммунизированных вакциной Гам-КОВИД-Вак (477 добровольцев), и переболевших COVID-19 (73 пациента) определяли в реакции нейтрализации, методами иммуноферментного анализа (ИФА) с использованием наборов реагентов различных производителей и иммуноблоттинга. Статистическую обработку результатов исследования проводили методами вариационной статистики.Результаты: установлено, что у 90,7% вакцинированных выявляются вируснейтрализующие антитела в реакции нейтрализации, и у 95,4% – в ИФА. Отмечено снижение уровня антител, выявляемых в реакции нейтрализации и ИФА, у вакцинированных старше 50 лет. Концентрация иммуноглобулина класса G к S-белку вируса SARS-CoV-2, определяемая в ИФА у группы лиц, иммунизированных вакциной Гам-КОВИД-Вак, достоверно выше, чем в группе переболевших COVID-19. Наибольший уровень корреляции результатов определения антител в ИФА и реакции нейтрализации получен при использовании экспериментального набора реагентов для количественного выявления вируснейтрализующих антител методом конкурентного ИФА с использованием рекомбинантного человеческого ангиотензинпревращающего фермента АСЕ2. Изучение динамики изменений уровня вируснейтрализующих антител показало, что через три месяца после введения второго компонента вакцины отмечается достоверное снижение уровня антител более чем в два раза.Выводы: у лиц, иммунизированных вакциной Гам-КОВИД-Вак, формируется эффективный гуморальный иммунитет к возбудителю COVID-19. Снижение среднего геометрического значения титров антител в два раза через три месяца после введения второго компонента вакцины Гам-КОВИД-Вак свидетельствует о необходимости проведения ревакцинации через 6 месяцев после введения второго компонента вакцины

Свойства гетерологичного иммуноглобулина против лихорадки Эбола после длительного хранения

Ebola outbreak in eastern parts of the Democratic Republic of the Congo in 2018–2020 proved that the virus remains highly hazardous for humans, and the outbreak in West Africa in 2014–2016, which was the largest Ebola outbreak in history, showed that it could be imported to other continents, including Russia. In 1993 the Federal State Budgetary Institution “48th Central Scientific Research Institute” of the Russian Ministry of Defence developed a specific equine immunoglobulin for emergency prophylaxis of Ebola in risk groups. The evaluation and improvement of the product’s properties is an important area in the development of biological defence technologies.The aim of the study was to examine the properties of the equine anti-Ebola immunoglobulin which had been stored for a long time at 2–8 °C.Materials and methods: the authors studied batches of heterologous anti-Ebola immunoglobulin that had been stored for 17–22 years. The properties of the product were evaluated according to the requirements of the State Pharmacopoeia of the Russian Federation, 14th ed. (Ph. Rus. 14 ed.). The specific activity of the product was determined in a plaque reduction neutralisation test using Ebola virus and African green monkey kidney cells (GMK-AH-1(D)). Immunoglobulin molecular parameters were determined by size-exclusion high-performance liquid chromatography using the test methods described in the European Pharmacopoeia 9.6 and Ph. Rus. 14 ed.Results: the storage of anti-Ebola immunoglobulin for 17–22 years at 2–8 °C resulted in a four-fold reduction of the level of virus-neutralising antibodies against Ebola, decrease in the proportion of monomers from 98 to 74–90%, increase in the proportion of dimers and polymers, and formation of immunoglobulin molecules’ fragments. Signs of toxicity for mice were observed in one of the three product batches. Conclusions: the obtained results suggest the need to perform more studies to test the quality of antiEbola immunoglobulin batches that were stored for shorter periods of time in order to assess the stability of their initial characteristics.Вспышка геморрагической лихорадки Эбола в восточных районах Демократической Республики Конго в 2018–2020 гг. показала сохраняющуюся высокую опасность вируса для человечества, а вспышка в Западной Африке в 2014–2016 гг., самая крупная с момента обнаружения вируса – возможность его ввоза в другие страны, в том числе в Россию. В ФГБУ «48 ЦНИИ» Минобороны России в 1993 г. разработан специфический лошадиный иммуноглобулин для экстренной профилактики лихорадки Эбола в группах риска. Изучение и совершенствование его защитных свойств является актуальным направлением разработки средств биологической защиты. Цель работы: оценить свойства иммуноглобулина против лихорадки Эбола из сыворотки крови лошадей после длительного хранения при температуре от 2 до 8 °С. Материалы и методы: серии гетерологичного иммуноглобулина против лихорадки Эбола, хранившиеся от 17 до 22 лет. Свойства иммуноглобулина оценивали согласно требованиям Государственной фармакопеи Российской Федерации XIV издания (ГФ РФ XIV изд.). Специфическую активность препарата определяли в реакции нейтрализации с вирусом Эбола в культуре клеток почки африканской зеленой мартышки (GМК-АН-1(Д)) методом подавления образования негативных колоний (бляшкообразования). Определение молекулярных параметров иммуноглобулина проводили методом эксклюзионной высокоэффективной жидкостной хроматографии согласно методикам, представленным в Европейской фармакопее 9.6 и ГФ РФ XIV изд. Результаты: хранение препарата иммуноглобулина против лихорадки Эбола в течение 17–22 лет при температуре от 2 до 8 °С привело к снижению уровня вируснейтрализующих антител к вирусу Эбола в 4 раза, уменьшению доли мономеров c 98 до 74–90%, увеличению доли димеров и полимеров, а также появлению фрагментов молекул иммуноглобулина. В одной из трех серий препарата была выявлена токсичность для белых нелинейных мышей. Выводы: полученные результаты свидетельствуют о целесообразности проведения дальнейших исследований по определению показателей качества серий иммуноглобулина против лихорадки Эбола, хранившихся менее продолжительные сроки, с целью оценки стабильности их исходных характеристик

The Study of Protective Properties of Vaccines against Virulent Strains of the Virus Tick-Borne Encephalitis Three Genotypes: European, Far Eastern and Siberian (Experimental Research)

Researches and presents comparative characteristics of protective properties of vaccines EC domestic and foreign production by immunization line BALB/c mice in a standard experiment for estimating the immunogenic activity against virulent strains of TBE virus three genotypes: genotype 1 - the strain «Sof'in», genotype 2 - strain «Absettarov», genotype 3 - strain «Lesopark». The results are of considerable interest in the evaluation of the efficiency and interchangeability of vaccines for the prevention of TBE in areas of natural foci of the disease in Russia. Currently, the circulation of the pathogen in the Russian Federation dominated by the TBE virus strains Siberian subtype (genotype) -more than 70% of virulent strains of TBE virus released into the natural foci of the Urals, Siberia, the Trans-Baikal. In studies on mice of BALB/c did not reveal significant differences in terms of protection (MID50 and DT50) against virulent strains of TBE virus three genotypes - the Far East, Europe and Siberia for three vaccines: «The vaccine encephalitis culture purified concentrated dry» (production Mikhail Chumakov Federal Research Centre for Research and Development of Immunobiological Preparations, Moscow), EntseVir (production Federal State Unitary Enterprise «Scientific and Production Association «Microgen»), FSME-Immun (Baxter AG production, Austria). Vaccines have shown good protection (protective) properties against 3 genotypes of TBE virus. Revealed a lower protective activity of vaccines Entsepur (manufactured by Novartis Vaccines and Diagnostics GmbH & Co. KG, Germany) strains of TBE 1 and 3 genotypes. These results confirm earlier studies to study the humoral response in mice BALB/c in the experiments with double and triple immunization

Properties of Heterologous anti-Ebola Immunoglobulin after Long Storage

Ebola outbreak in eastern parts of the Democratic Republic of the Congo in 2018–2020 proved that the virus remains highly hazardous for humans, and the outbreak in West Africa in 2014–2016, which was the largest Ebola outbreak in history, showed that it could be imported to other continents, including Russia. In 1993 the Federal State Budgetary Institution “48th Central Scientific Research Institute” of the Russian Ministry of Defence developed a specific equine immunoglobulin for emergency prophylaxis of Ebola in risk groups. The evaluation and improvement of the product’s properties is an important area in the development of biological defence technologies.The aim of the study was to examine the properties of the equine anti-Ebola immunoglobulin which had been stored for a long time at 2–8 °C.Materials and methods: the authors studied batches of heterologous anti-Ebola immunoglobulin that had been stored for 17–22 years. The properties of the product were evaluated according to the requirements of the State Pharmacopoeia of the Russian Federation, 14th ed. (Ph. Rus. 14 ed.). The specific activity of the product was determined in a plaque reduction neutralisation test using Ebola virus and African green monkey kidney cells (GMK-AH-1(D)). Immunoglobulin molecular parameters were determined by size-exclusion high-performance liquid chromatography using the test methods described in the European Pharmacopoeia 9.6 and Ph. Rus. 14 ed.Results: the storage of anti-Ebola immunoglobulin for 17–22 years at 2–8 °C resulted in a four-fold reduction of the level of virus-neutralising antibodies against Ebola, decrease in the proportion of monomers from 98 to 74–90%, increase in the proportion of dimers and polymers, and formation of immunoglobulin molecules’ fragments. Signs of toxicity for mice were observed in one of the three product batches. Conclusions: the obtained results suggest the need to perform more studies to test the quality of antiEbola immunoglobulin batches that were stored for shorter periods of time in order to assess the stability of their initial characteristics