Vol 97, No 4 (2020)

The results of the predictive analytical studies on Covid-19 incidence dynamics in Moscow, taking into account different changes in epidemic prevention measures, including vaccination coverage of the population, are presented.
Research Objective. Using the new epidemiological model for analysis and prediction of the Covid-19 incidence dynamics in Moscow and outlining main strategies in implementing epidemic prevention measures (EPMs), including vaccination in 2020/2021.
Materials and methods. The epidemiological model is based on the Russian approach to mathematical modeling of epidemics, known as Epiddynamics. The medium-term forecasting incorporated probable scenarios of epidemic development with different EPMs (isolation of the infected and contacts, breaking the transmission chains), including different rates of vaccination coverage in Moscow.
Results and discussion. The computational simulations demonstrated that the incidence rate is likely to increase with scaling down EPMs and zero vaccination coverage. At the same time, the daily incidence rate depends on the degree of EPMs reduction and basically does not depend on the time when the reduction begins. With scaled-down EPMs, vaccination can decrease the incidence, though its effectiveness will depend on the time of its commencement, coverage and rate.
Conclusion. The computational simulations showed that the vaccination will be efficient for prevention of new surges in COVID-19 cases only if the other EPMs (isolation of the infected and contacts, breaking the transmission chains) are still in place until the vaccination coverage reaches about 2 million people. Ideally, the measures aimed at isolation and breaking of transmission chains should be continued until the total vaccination coverage reaches 4 million people, after which the restrictive measures can be scaled down significantly. With vaccination coverage of 50% of the population of Moscow, the restrictive measures can be completely discontinued.

Introduction. An increasing incidence of pertussis among different groups of population and shortcomings of the existing preventive solutions pinpoint urgency of development of new safe vaccines suitable for immunization of infants and for booster immunization of adolescents and adults.
The purpose of this study is evaluation of safety, immunogenicity and protective activity of the new constructed attenuated Bordetella pertussis bacteria 4MKS by infecting immunized Macaca mulatta monkeys intranasally with virulent bacteria of the pertussis pathogen.
Materials and methods. Five adult, clinically healthy Macaca mulatta monkeys aged 3–4 years were used for immunization and experimental infection. The re-immunization was performed in 6 months. Three non-immunized animals of the same age were used as controls.
Results. The intranasal single-dose inoculation and re-inoculation of attenuated B. pertussis bacteria did not cause any nasopharyngeal inflammation in the rhesus monkeys and any changes in the blood lab test values after the nonhuman primates had been infected with virulent bacteria. No elevation of total IgE was detected in blood serum of the Macaca mulatta monkeys after the single-dose and double-dose immunization. When the monkeys were intranasally immunized with attenuated and virulent B. pertussis bacteria, they developed a defensive reaction to re-infection, namely suppression of the bacterial growth, increased rates of elimination of bacteria from the animals’ nasopharynxes and development of a humoral immune response to the infection. The development of immunity against pertussis re-infection is accompanied by a pronounced booster effect.
Discussion. The obtained results suggest common mechanisms of development both of post-vaccination immunity after intranasal vaccination of animals and infection-acquired immunity against pertussis. Both of them provide protection against re-infection with B. pertussis bacteria and prevent development of clinical symptoms of pertussis.

Introduction. The study of the protein composition of the causative agent of anthrax — Bacillus anthracis, allows you to identify both general species and individual characteristics of strains that differ in phenotypic properties, manifested mainly in the vegetative form and which are important for virulence, immunogenicity and the ability to adapt to different vegetation conditions.
Purpose of the work. In the group of anthrax microbe strains having different plasmid composition and virulence, different methods of extraction of the total proteome from vegetative bacillus cells have been tested.
Results. In the course of the work, it was shown that the rate of spore formation varies significantly between individual strains of the anthrax microbe and can have a significant impact on the efficiency of extraction and the composition of the protein complex. Preliminary treatment with lysozyme, which affects the cell membrane, promotes a more complete lysis of cells, and ultramicrocentrifuge filtration provides complete specific sterility of the obtained samples.
Conclusion. A culture preparation scheme was developed for B. anthracis, which allows one to obtain a culture in the vegetative phase of the life cycle and to efficiently extract proteins in combination with reliable disinfection of samples.

The SARS-CoV-2 virus is a pathogen causing the coronavirus infection that culminated in a worldwide pandemic in 2020. It belongs to β-coronaviruses and has high genetic similarity to the SARS-CoV virus that is responsible for an outbreak of severe acute respiratory syndrome in 2002–2003. The analysis of molecular interactions shows that SARS-CoV-2 has higher virulence due to lower binding free energy in interaction with the angiotensin-converting enzyme 2 (ACE2), which is used by the virus to enter the host cell. At the time of the global coronavirus pandemic, the thorough study of ACE2 as a key component of the disease pathogenesis comes to the fore. The detailed study of the enzyme, which is a receptor located on the surface of different tissues and which normally catalyzes the conversion of angiotensin II to angiotensin (1–7), led to diverging conclusions. Being non-tissue specific, the receptor is abundantly present in the heart, kidneys, small intestine, testes, thyroid, and adipose tissue. Besides regulating blood pressure, it suppresses inflammation, mainly in the lung tissue, participates in amino acid transport and maintains the activity of the gut microbiome. With all its essential positive functions, the role of ACE2 is highly ambiguous, specifically in coronavirus infection. The influence on the renin-angiotensin system can be seen as a promising therapeutic route in treatment of coronavirus infection. The preliminary data on using of ACE2 inhibitors, soluble forms of ACE2, and angiotensin II receptor blockers demonstrate their effectiveness and, consequently, improvement in symptoms and prognoses for patients with coronavirus infection. The review presents information about ACE2 distribution in human tissues, explores its interaction with SARS-CoV-2, provides a theoretical basis for medications involving ACE2 metabolic pathways and for using them in treatment of coronavirus infection and its prevention.

The review presents the basic information available in literature on the use of gas chromatography-massspectrometry. Issues concerning the significance of this method for the identification of microorganisms are discussed. The prospects of creating domestic software and databases of mass spectra of microorganisms are noted.

Introduction. Rotavirus infection (RVI) is the most common cause of severe gastroenteritis in infants and young children worldwide: 600,000 children die annually; it accounts for approximately 3 million hospitalizations and 25 million physician visits each year among children. Preventive vaccination is universally recognized as the most effective measure against this infection.
The purpose of the study is assessment of reactogenicity, safety and immunogenicity of the pentavalent live vaccine for RVI prevention in childhood immunization.
Materials and methods. The first multicenter prospective, randomized, double-blind, placebo-controlled clinical trial of the pentavalent live vaccine for RVI prevention was conducted in Russia among healthy infants aged 2 months at the time of the first vaccination.
Results. The vaccine had a satisfactory safety profile and high immunologic activity when administered in a threedose series for childhood immunization. No negative changes in the children’s health condition were detected during the surveillance monitoring.
Discussion. The seroconversion rates, the seroconversion factor and the geometric mean antibody titer were consistent with the results obtained during trials of the above vaccine and its equivalents in other countries.