Relevance. During the COVID-19 pandemic, an early determination of the start of the influenza epidemic by the incidence of influenza and SARS in total is impossible, due to the similarity of the clinical picture of SARS and lung cases of COVID-19.

Aim. The goal is to calculate and test new criteria for early detection of the start of influenza epidemics and their intensity for each of the cities–reference bases (61) of the 2 WHO National Influenza Centers based on the incidence of clinically diagnosed influenza.

Tasks. To evaluate the effectiveness of baseline influenza incidence and epidemic intensity thresholds for the general population and age groups of each city in the epidemic of 2022–2023. To give a retrospective assessment of the effectiveness of influenza baselines for cities, compared with the baselines of the corresponding Federal Districts, for the seasons from 2009 to 2022. To estimate the intensity of epidemics by influenza incidence over the previous epidemies of the pandemic cycle of influenza A/California/H1N1/ virus.

Materials and methods. By the 2022–2023 season. baseline lines and thresholds of influenza incidence intensity were calculated using the method of moving epidemics according to clinical diagnostic data not only for federal districts, but also for each of the observed cities (61). The calculation of the baselines was carried out according to the data of the computer database of the Influenza Research Institute on the incidence of influenza by age groups in each city over the previous 5 years in the season from 2016–2017 to 2021–2022.

Results. In the 2022-23 season application of new criteria for the start of epidemics (prev.- and post-epidemic baseline influenza incidence) and their intensity revealed: early onset of the influenza epidemic (07–13.11 2022); simultaneous onset in all children's age groups; geographical spread of the epidemic in federal districts; intensity of the epidemic in the general population and age groups. The thresholds for the intensity of influenza morbidity made it possible to clarify the intensity levels of influenza epidemics from 2009 to 2023 and to show that the pandemic cycle of the influenza A(H1N1) virus continues. A comparison of the effectiveness of urban baselines with federal ones in the epidemic of 2022–2023 showed that urban baseline flu incidence lines revealed the start of epidemics 1–3 weeks earlier: among the general population in 12 cities, persons over 15 years old – in 9, children 3–6 years old – in 6 and 7–14 years old – in 5. A retrospective assessment of the effectiveness of city and federal influenza baselines (from 2009 to 2022) showed their effectiveness both in the seasons from 2009 to 2016 (before the baseline calculation period) and after. The effectiveness of urban baselines for early detection of the start of epidemics depended on the etiology of the epidemic – more with influenza A(H3N2) than with influenza A(H1N1), the level of intensity of influenza diseases and the age group of the population (more in children with low intensity and in adults with an average level).

Conclusion. The results obtained on the basis of population epidemiological data on the incidence of influenza, namely, new criteria for detecting the start of an epidemic in cities, can be used in health management bodies in cities and subjects of the Russian Federation for early detection of epidemics and management decisions, timely introduction of anti-epidemic measures, creating a stock of medicines. The expected effect of the method of early epidemiological diagnosis of epidemics is a decrease in morbidity, etc.

Relevance. One of the most affected by the new coronavirus infection (COVID-19) groups of the population were medical workers who have high risks of infection in the performance of professional duties

Aim. Analysis the clinical manifestations of COVID–19 in different periods of the pandemic in medical organizations, taking into account the genetic variability of circulating strains of SARSCoV- 2 and vaccination status.

Materials and methods. To study the clinical manifestations of coronavirus infection, an online survey of medical workers in a large industrial region was conducted in March 2022 using a specially designed anonymous questionnaire. The total number of respondents was 3,078. Clinical manifestations were analyzed during five epidemic rises in the incidence of COVID-19 from March 2020 to March 2022. To assess the SARS-CoV-2 virus strains circulating in the region, data from the GISAID database (the first and second waves of the pandemic, n = 298) and the results of PCR studies in the laboratory of UMMC-Health LLC (third - fifth waves, n = 349) were used.

Results and discussion. In the first and second epidemic rises of morbidity associated with SARS-CoV-2 strains B.1. and B.1.1, the structure of clinical forms did not significantly differ: 3.6% and 3.9% were asymptomatic forms, 61.3% – variants of acute respiratory infection (AR I) and 35.1% and 34.8% - pneumonia, accordingly. In the third epidemic upsurge caused by the Delta variant (V.1.617.2), the structure of clinical forms did not undergo significant changes. In the fourth epidemic rise in morbidity, also associated with the spread of the Delta variant, the share of ARI in the structure of clinical forms increased to 77.0%, and pneumonia decreased to 21.3%.In the fifth wave of the pandemic caused by the Omicron gene variant (B.1.1.529), there was an increase to 91.3% of the proportion of mild clinical forms and a decrease to 7.1% of forms with lung damage. The frequency of detection of general infectious symptoms, upper respiratory tract lesions and neurological manifestations of COVID-19 had statistically significant differences in different periods of the pandemic. Whereas the frequency of gastrointestinal disorders did not significantly differ. The high clinical efficacy of vaccination has been shown – in ter ms of a 3.6-fold reduction in the chances of developing moderate and severe forms of the disease.

Conclusion. Based on the results of the study, new data were obtained on the features of the clinical manifestations of COVID-19 in different periods of the pandemic with the change of genetic variants of the pathogen and the role of vaccination in preventing the development of moderate and severe clinical forms of infection was shown.

Relevance. The Altai Krai (AK) is among the least prosperous subjects of the Russian Federation in terms of the incidence of acute respiratory infections (ARI).

Aim: to analyze the causes and conditions for the formation of a high incidence of ARI among the population of the Altai Krai based on an assessment of the long-term and intra-annual dynamics of the epidemic process in 2011–2021.

Materials and methods. In the course of a retrospective epidemiological study according to the annual forms No. 2 of the state statistical observation (SOS) for 2011-2021 a comparative analysis of the incidence of ARI and community-acquired pneumonia (CAP) in various groups of the population of the AK, the Siberian federal district (SFD) and the population of the Russian Federation as a whole was carried out. Data for 2020–2021 («covid» period) was analyzed separately in comparison with the precovid period of 2011–2019. The intra-annual dynamics of the incidence of ARI and CAP in the AK were studied using the method of trend-seasonal decomposition according to the monthly forms No. 2 of the SOS.

Results and discussion. It is established that in 2011–2021. the epidemic process of ARI in the AK was characterized by a higher level and rate of increase in the incidence of all population groups (adults and children, urban and rural) compared to the all-Russian and average for the Siberian Federal District; a higher proportion of children in the overall structure of ARI cases, despite the fact that the proportion of the child population did not exceed (or was even less) than in other regions; no decrease in the incidence of ARI in children in the period 2020–2021; the presence of a trend towards an increase in the incidence of ARI in both urban and rural residents in the pre-covid period; higher incidence in the rural population in 2011–2019 compared to the whole of the Russian Federation or the Siberian Federal District. A less pronounced role of the seasonal component in the registration of CAP was revealed, in comparison with ARI. In some years, an increase in the registration of CAP was observed in the spring-summer period. For 2020-2021 there was a close coincidence of the curves of the intra-annual dynamics of the registered incidence of ARI and COVID-19 among the general population, CAP and COVID-19.

Conclusion. The obtained results indicate the need to study the possible impact of environmental factors, as well as the shortcomings of the etiological interpretation and differential diagnosis of some natural focal and zoonotic infections that occur with fever and respiratory symptoms on the formation of a high incidence of ARI in the Altai Territory.

Relevance. According to WHO, the number of patients with a new coronavirus infection amounted to more than 676 million people for the period from January 2020 to January 2023. It is obvious that the consequences of COVID-19 will prevail in medical practice in the coming years, so medical rehabilitation should be the focus of attention when providing medical care to patients with coronavirus infection.

Aims. To investigate the approach to physicians' selection of rehabilitation interventions for patients who have undergone Covid-19.

Materials and methods. The analysis of 1832 case histories of patients of one of the temporary covid hospitals in Moscow, who are being treated in the hospital in 2020–2022, was carried out. Statistical analysis was carried out using the StatTech v. 3.1.3 program (developed by Stattech LLC, Russia). Predictive models characterizing adherence to rehabilitation measures were developed using the logistic regression method.

Results and discussions. The analysis of predictors of statistically significant regression models showed that when deciding on the appointment of rehabilitation measures or additional consultation when a patient is discharged from the hospital, doctors rely on pathologies already present in patients before COVID-19 disease, without taking into account the occurrence of possible pathology after a new coronavirus infection in any organ system. For example, the appointment of a cardiologist's consultation increases 6 times in the presence of a history of cardiovascular diseases or atherosclerosis and 10 times in the presence of cardiovascular diseases and atherosclerosis at the same time. The presence of bronchial asthma increased the probability of consulting a pulmonologist by almost 3 times, and in the absence of diabetes mellitus, the probability of getting additional advice from an endocrinologist decreased by 11 times.

Conclusions. An individual rehabilitation plan should take into account the severity of the COVID-19 disease, the degree of damage to the lung tissue, heart, blood vessels and other organs. The regression models can be used for economic analysis in order to identify the need for working hours and the number of medical workers necessary to ensure the optimal volume and effectiveness of rehabilitation measures for patients who have suffered a new coronavirus infection.

Relevance. COVID-19 remains an urgent disease for long-term care institutions (LTCI), because local outbreaks of COVID-19 continue to be registered in 2022 and in 2023.

Aims. To study the epidemic process of COVID-19 in LTCI (nursing homes, neuropsychiatric boarding schools) in Moscow for 2020–2022.

Materials and methods. The analysis of the epidemic process of COVID-19 in LTCI was carried out for the period 2020–2022. Data of Automatic information system «Department of Registration and Accounting of Infectious Diseases was used: 5390 COVID-19 residents and employees of 28 institutions in Moscow and 3,239,617 residents of Moscow; 15 acts of epidemiological investigation of the focus of infectious disease in the period from 2020 to 2022.

Results. In total, 9 increases in the incidence of COVID-19 were registered. The first rise was the most intense, which affected morbidity (81.14 per 1,000 beds per week), indicators of activity of epidemic foci (KO – 100%, IO – 21.08, R – 20.08), mortality (for 2020 – 32.6%). In the first rise of morbidity in nursing homes, there is a direct correlation of a high degree of connection with the morbidity of the population of Moscow (r = 0.906), and for subsequent rises there is a noticeable relationship (r = 0.580) at p<0.05. From 2 to 9 rises, the incidence tended to decrease. All the rises of COVID-19 occurred due to the formation of foci in institutions where the source of infection was employees. For 2020–2022, the proportion of severe cases of infection with a fatal outcome among residents ranged from 14.6 ±6.7% to 31.8 ± 6.5%.

Conclusion. The analysis of the manifestations of the COVID-19 epidemic process in long-term care institutions in Moscow for 2020–2022 allowed us to distinguish two stages of morbidity.

Relevance. Infections caused by methicillin-resistant strains of Staphylococcus aureus are an urgent problem of hospital epidemiology, and control measures involve the development of new antimicrobials. Probiotics based on bacterial strains isolated fro natural habitats are considered promising means of combating MRSA.

Aims. To test the possibility of using the Bacillus safensis 440-1 strain isolated from Antarctic soil. as an antibacterial agent for the treatment of experimental staphylococcal infection.

Purpose of the study – check the possibility of using the Bacillus safensis 440-1 strain, isolated from Antarctic soil, as a topical antibacterial agent for the treatment of experimental staphylococcal infection.

Material and methods. The potential virulence of Bacillus safensis strain 440-1 was studied on a mouse peritonitis model, and its activity against the methicillin-resistant Staphylococcus aureus SA776 test strain was studied on a localized wound infection model.

Results and discussion. Our study demonstrated the safety of the tested strain due intraperitoneal use. We found that the use of the studied strain reduces the staphylococci amount in wounds from the third day from the start of the study to the end of the observation period, without aggravating the course of the infection.

Conclusion. Bacillus safensis strain is a promising potential probiotic and it can be used as a part of complex antiseptic or disinfectant after additional studies aimed at developing an optimal mode of its use.

Relevance. Hemorrhagic fever with renal syndrome (HFRS), due to the severity of the course and high mortality, poses a serious threat to the health of the population of both the city of Sochi and its guests. Therefore, in order to implement more effective and less economically costly anti-epidemic and preventive measures, it is very important to constantly monitor the activity of the natural focus of HFRS, as well as to have a clear idea of the territories most dangerous for the risk of infection with this infection.

Aims. Assessment of the epidemiological significance of the territory of the city of Sochi for the risk of infection with HFRS based on the maximum entropy method using a geographical information system.

Materials & Methods. Based on the application of the maximum entropy algorithm implemented in the MaxEnt program, as well as the ArcGIS 10 program.8. Ranking of the territory of the city of Sochi according to the risk of infection with HFRS was performed. The paper uses: data on positive epizootological findings (a total of 131) for 2016-2021, which were obtained from the Sochi branch of the Federal Medical Institution «Center of Hygiene and Epidemiology in the Krasnodar Territory», the Sochi branch of the Federal Medical Institution «Black Sea Plague Station» of Rospotrebnadzor, as well as the Stavropol Plague Control Research Institute of the Rospotrebnadzor; materials on environmental conditions from the Biolclim data bank, vegetation index for 9 months (https://land.copernicus.eu/global/products/NDVI ). Preliminary preparation of the information was carried out using the ArcGIS 10 program.8. As a tool for building a training model, the MaxEnt program version 3.4.4 was used (https://biodiversityinformatics.amnh.org/open_source/maxent /).

Results and discussion. The practical implementation of the tasks was to obtain maps of the epidemiological significance of the territory for the risk of infection with HFRS by superimposing the points of occurrence of the species (reservoir and carrier of HFRS) on maps of abiotic environmental factors affecting its spread. The implementation of this work consisted of the sequential implementation of four main stages: the first – the collection, generalization and transformation of bioclimatic and epizootic-epidemiological data; the second – the selection of the most significant data for the construction of the model; the third – the ranking of the territory of the city. Sochi on the risk of the spread of HFRS using GIS; the fourth is the analysis of the data obtained. In the course of the work, a model was obtained that allows dividing the study area according to the degree of risk of infection with HFRS with a high degree of reliability and significant prognostic value.

Conclusions. The use of the model makes it possible to obtain new, more detailed data from a spatial point of view on the boundaries of potentially dangerous sites in the region in terms of GLPS. In particular, this applies to those territories where positive epizootological findings and cases of infection with HFRS have not been previously noted.

Relevance. The emergence of a new SARS-COV-2 coronavirus in early 2020 radically changed the seasonal pattern of influenza and other acute respiratory infections worldwide. Along with a decrease in the frequency of RSV infection, the number of diagnosed cases of influenza virus infection decreased by 99% during the COVID-19 pandemic. Vaccines are known to be the best tool at our disposal for preventing infectious diseases and reducing the risk of serious complications and deaths. The Russian Federation has great experience in developing vaccines against viral and bacterial infections and is constantly improving the technology of their production putting new vaccine preparations into circulation. Domestic vaccines against a new coronavirus infection caused by SARS-CoV-2 virus were developed in the shortest possible time. This work evaluated the efficacy of Gam-Covid-Vac (Sputnik V) and CoviVac vaccines during periods of circulation of different variants of SARS-CoV-2 «Delta» and «Omicron» in St. Petersburg.

Aims. To evaluate the prophylactic efficacy of domestic vaccines Gam-Covid-Vac (Sputnik V) and CoviVac in the epidemic season 2021–2022 in the periods of SARS-CoV-2 «Delta» and «Omicron» variants circulation in Saint-Petersburg.

Materials and Methods. Vaccination and follow-up of vaccinated subjects was initiated in February 2021, with the arrival of the Gam-Covid-Vac (Sputnik V) and CoviVac vaccines at the specialized clinic of Smorodintsev Research Institute of Influenza. Follow-up of vaccinated subjects for one year after vaccination included 346 men and women aged 19-85 years, who were interviewed in two telephone surveys.

Results. Telephone interviews among individuals vaccinated with Gam-Covid-Vaс (Sputnik V) and CoviVac vaccines revealed that during the circulation of «Delta» variant, 2nd half of 2021, COVID-19 disease occurred in 16.3% of people vaccinated with the CoviVac vaccine and in 15.8% of those vaccinated with Sputnik V vaccine – differences between groups were not statistically significant (p > 0.05). COVID-19 disease in both vaccine groups was predominantly mild with 61.95% of observed falling ill in the CoviVac vaccine group and 84.4% (slightly more, 1.4-fold) in Sputnik V vaccine group. At the same time, moderate and severe diseases were slightly more in absolute value among those vaccinated with "CoviVac" vaccine. Cough, lung damage from 30% to 80%, loss of sense of smell and taste dominated among the symptoms in both groups of patients. During the second observation period (January-April 2022), when «Omicron» variant were actively circulating, the number of cases among CoviVac and Sputnik V vaccines was 37.5% and 43.8%, respectively; the differences between the vaccine groups were not statistically significant (p > 0.05). During this period, diseases in CoviVac and Sputnik V vaccine groups were predominantly mild in 84.4% and 90.5%, respectively, with statistically insignificant differences. There were also no significant differences in cases of moderate severity. Among those observed in « CoviVac» group during this period, a greater number of diseases, in absolute value, proceeding in a severe form and requiring hospitalization was noted. Clinically, the diseases caused by «Omicron» variant manifested in symptoms characteristic of flu and common cold: headache and muscle pain, fever, chills, chest pain, nasal congestion, severe fatigue, fatigue, weakness.

Conclusions. During periods of active « Delta» variant circulation in the fall of 2021patients vaccinated with SARS-COV-2 coronavirus vaccines were 2.3 to 2.8 times less ill than during circulation periods of «Omicron» variants ВА.1 и ВА.2 in January-April 2022: 16.3% and 15.8%, 37.5% and 43.8%, respectively. Mild COVID-19 disease predominated among patients vaccinated with both vaccines during periods of circulation of «Delta» and «Omicron» variants. Differences in the manifestation of clinical symptoms of the disease in the periods of circulation of different strains were noted. It was shown that the vaccines against SARS-CoV-2 infection Gam-Covid-Vac (Sputnik V) and CoviVac do not protect 100% against the disease, but protect against a severe course of the disease and lethal outcomes.

Relevance. On the territory of the Russian Federation, mass vaccination of the population is recognized as a priority health strategy against COVID-19, Gam-COVID-Vac vaccine has been widely used. The main risk group, which is subject to priority vaccination, are employees of medical organizations (MO). The determination of IgG to SARS-CoV-2 is an important parameter for assessing the intensity and duration of post-vaccination immunity

Aims. Study the immunological efficacy of the vaccine Gam-COVID-Vac used by employees of a psychiatric hospital and a regional hospital.

Materials and methods. A study of the blood sera of 410 employees of two MO of various profiles who received one full course of the Gam-COVID-Vac» vaccine for the presence of IgG to RBD Spike SARS-CoV-2 using a set of reagents «SARS-CoV-2-IgG quantitative-ELISA-BEST» and IgG to NC SARS-CoV-2 using a set of reagents «ELISA anti-SARS-CoV-2 IgG».

Results and discussion. Specific IgG to RBD Spike SARS-CoV-2 after vaccination with «Gam-COVIDVac » were found in 92.9% of psychiatric hospital staff and 98.0% of the regional hospital. Antibodies of class G to SARS-CoV-2 with a level of 300 BAU/ml or more were detected in 11.6% of psychiatric hospital staff and in 70.0% of regional hospitals, which is associated with the smallest proportion of persons in a psychiatric hospital with hybrid immunity than in a regional hospital (67.4% vs. 89.0%, respectively). A study of employees of the Ministry of Defense of various profiles revealed a difference in the level of IgG to RBD Spike SARS-CoV-2: 178.0 BAU/ml in a psychiatric hospital and 366.0 BAU/ml in a regional hospital. In a psychiatric hospital, the IgG level was highest up to 3 months after the completed vaccination – 166.4 BAU/ml, in a regional hospital from 3 to 6 months – 362.8 BAU/ml, then the number of antibodies decreases, which indicates the importance of monitoring for class G antibodies to SARS-CoV-2 at different times after vaccinations. Among the employees of the two MO, mild forms of the COVID-19 disease prevailed.

Conclusion. Thus, the high immunological effectiveness of vaccination against COVID-19 with Gam-COVID-Vac was established in a group of employees of two MO, and the need for serological monitoring for the purpose of revaccination was also shown.

Relevance Invasive meningococcal infection (IMI) is a significant clinical problem and is associated with a high probability of severe complications and death. Vaccination programs against meningococcus can achieve significant clinical effectiveness and require significant financial costs. This makes it relevant to study the economic burden of meningococcal infection in the conditions of modern healthcare in order to obtain basic data for subsequent research in the field of evaluation of medical technologies.

Aims. To assess the economic burden of IMI in children in the conditions of healthcare in the Republic of Belarus

Material and methods: a retrospective study using the "cost of illness" method was conducted for 22 children hospitalized in the city children's infectious clinical diseases hospital in 2018-2019. All values are presented in belarusian rubles. The average ± standard deviation, minimum – maximum values, median [Q1, Q3], cost shares (%) are calculated for the cost values. The minimum– maximum values and median [Q1, Q3] were calculated for the age of the patients.

Results: taking into account the costs of treatment in healthcare organizations of all patients studied, the share of direct costs of hospitalization was 29.0%, the share of direct costs of diagnosis – 7.2%, the share of direct costs of pharmacotherapy - 8.3%. A significant part of the costs accounted for observations after discharge and amounted to 55.4%.

Conclusion: a retrospective study of the economic burden of MI in the Republic of Belarus using the "cost of illness" method in patients hospitalized in a public health organization demonstrates a significant economic burden of this disease, which in the long term is primarily due to the presence of complications in the patient, as well as the impact of the patient's death on the value of total costs. The data obtained can be used in conducting national research on the evaluation of medical technologies.

Relevance. Listeria monocytogenes is a ubiquitous bacterium that causes listeriosis, which represents a widespread infectious disease currently inflicting great damage to livestock production and posing a serious threat to human health.

Aim. To analyze the population structure and assess the pathogenic potential of Listeria monocytogenes isolates isolated on the territory of the Russian Federation.

Materials and methods. A total of 79 listeria isolates were isolated from food products. Species identification and phenotypic analysis for antibiotic resistance were performed using VITEK MS system (bioMerieux, Marcyl’toile, France). Thirty-five antibiotic-resistant isolates were characterized by analysis of whole-genome sequencing data.

Results. Whole genome sequences of thirty-five antibiotic-resistant Listeria monocytogenes isolates of food origin were analyzed. We determined clonal structure of this population and revealed a small number of antibiotic resistance determinants (fosX, tetM и сlpL), extensive set of virulence factors, as well as the presence of CRISPR/Cas systems. Most of the isolates belonged to phylogenetic line II and were divided into nine clonal complexes with the prevalence of CC121, which was one of the epidemiologically significant genetic clones. Two CC2 isolates belonging to the most pathogenic phylogenetic lineage I were also found. Thirteen isolates were characterized by the presence of putative CRISPR/Cas systems of IB and IIA types. All ST 121 isolates contained two types of identified adaptive immunity systems simultaneously in their genomes. Correlation analysis confirmed their functionality.

Conclusion. We believe that the whole genome data obtained for the foodborne Listeria monocytogenes isolates will facilitate and complement further epidemiological studies of this pathogen, as well as the investigations of its genome variability in terms of the acquisition of various genetic elements associated with adaptation, antimicrobial resistance, and virulence. Moreover, the results of such studies will help to develop preventive measures to effectively solve problems associated with the bacterial contamination of animal products and ensure food safety in production conditions and the «farm-to-table» chain.

Relevance. Widespread use of endoscopic methods in diagnosis and treatment increases the potential risks of infection of patients in case of improper handling of flexible endoscopes. The main cause of the problem is inattention, low level of competence of personnel. One of the best solutions to this problem is to provide documentation (standard operating procedure – SOP) regulating the processes of handling flexible endoscopes in medical organizations in order to minimize the human factor.

Aim. The Development of the SOP for processing of a flexible nasal pharyngeal mirror adjusted for the epidemiological risks of nonsterile endoscopic interventions.

Materials & Methods. The epidemiological risks of non-sterile endoscopic interventions were evaluated on the basis of scientific publications and statutory regulations, and the example of SOP was introduced for the flexible nasal pharyngeal mirror.

Results. Considering the factors, causing development of infections, related to delivery of health care, and requirements of the sanitary law, a sample of SOP was designed for manual processing of the flexible nasal pharyngeal mirror. Moreover, The main courses were defined, which should be followed by health-care workers while developing of SOP in a healthcare organization.

Conclusions. The standardization of the procedure of processing of the flexible endoscopes allows to perform manipulations after clearly developed algorithm, excludes misunderstanding from the stuff, reduces the quantity of faults and mistakes and, as result, reduces probability of the healthcare-associated infections (HAI).

Relevance. COVID-19 vaccination reduces mortality and the course of severe diseases. However, there is an insufficiency of studies evaluating factors leading to infection among COVID-19 vaccinated individuals.

Aim. Identification of epidemiological features that distinguish cases of the disease in vaccinated and unvaccinated cohorts.

Materials and methods. The analysis of the incidence of COVID-19 in 1126 hospitalized patients in the period from 23.06.2021 to 01.05.2022 was carried out taking into account the presence or absence of vaccination against the SARS-CoV-2 virus.

Results. It was found that the risk of COVID-19 getting sick in the unimmunized was 1.5 times higher than in the vaccinated (p < 0.05). The incidence of hospitalization, due to the severity of the condition (moderate, severe and extremely severe), in unvaccinated people with no history of comorbidities, is more than 3 times higher than in vaccinated people (p < 0.05) in the same group. The probability of death from COVID-19 among vaccinated people is 1.5 times lower than among unimmunized people (p < 0.05). The age characteristic of mortality in vaccinated people shifts to the «senile» age (76.93 ± 1.32), while among the unimmunized, the age of death is closer to the category of «elderly» (73.74 ± 1.39 years) (p ≤ 0.05). In the structure of mortality among the vaccinated, the main share was made up of patients with a history of 3 to 7 concomitant systemic diseases (66.7%), while among the unvaccinated, the main share (74.5%) were patients either without comorbidities or with a history of 1 to 2 concomitant diseases.

Conclusion. The results of the epidemiological features of the COVID-2 epidemic process have shown that vaccination against the SARS-CoV-2 virus is vital for elderly and senile people with comorbid conditions.

Relevance. Hepatitis B often causes liver cirrhosis and hepatocellular carcinoma, especially among patients with HIV. Vaccination is the main prophylaxis of HBV for preventing infection and developing chronic disease. Studying the duration of postvaccination immunity and the expediency of revaccination in different age and risk groups is important for improving the strategy of immunoprophylaxis of B hepatitis.

Aims. Study was to determine the level of post-vaccination immunity to HBV and specific antibodies (anti-HBc and anti-HBs) among HIV-positive patients and the healthy population of Novosibirsk and Tomsk.

Materials and methods. 536 blood samples were taken from HIV-positive patients and 337 blood samples from healthy people (pregnant women and persons undergoing a routine medical examination). The presence of HBsAg, anti-HBs IgG, and anti-HBcIgG were determined in the samples.

Results. The proportion of post-vaccination immunity decreased in older age groups with an increase in the proportion of post-exposure immunity. The proportion of HIV-positive patients who had contact with HBV was higher than among healthy people. Around 70% of people in each group had a low level of protective antibodies anti-HBs (lower than 100 IU). A high level of anti-HBs (higher than 400 IU) was determined in 10% of examined people. The proportion of low levels of anti-HBs increased with age, while average and high levels of post-vaccination immunity were less common with increasing age.

Conclusion. A low proportion of HIV-positive people, who have been effectively vaccinated against hepatitis B, was noticed. Annual blood tests for the presence of HBsAg, anti-HBs, and anti-HBc, in combination with determining DNA HBV, can be recommended for HIV-positive patients who have a risk of developing an occult form of hepatitis B.

Relevance. Human Noroviruses (HuNoV) are highly contagious pathogens responsible of acute human norovirus infection. HuNoV is the cause of every fifth case of acute non-bacterial gastroenteritis, annually causing about 699 million cases of the disease and more than 200 thousand deaths worldwide. Controlled expression of the HBGA antigens by the FUT2 gene causes resistance to human norovirus. Polymorphisms of the FUT family genes contribute to partial or complete immunity to certain genogroups/ genotypes of norovirus.

Aims. To characterize the effect of FUT2 gene polymorphisms on susceptibility to HuNoV.

Results. Nonsensemutations of G428A in two homologous alleles contribute to the formation of a secretory-negative phenotype (se), which is a factor determining immunity to noroviruses. Some missense-mutations in the nucleotide positions se385,571 form partial resistance against certain genotypes. People with a secretory-negative phenotype are immune to infection by the GII.4 genotype and its genovariants.

Conclusions. The expression of HLA antigens by the functionally inactive FUT2 gene plays a key role in the resistance of the human population to HuNoV. Susceptibility to HuNoV largely depends on the prevalence of HBGA phenotypic diversity among ethnic populations around the world. Targeted screening aimed at identifying polymorphisms of the FUT family will allow identifying risk groups more susceptible to HuNoV.

Relevance. The globalization of the epidemic process requires improved surveillance of infectious diseases, in particular tuberculosis.

Methods of molecular and genomic analysis are the most informative approaches that can radically change the management of this disease.

Aims. To substantiate the necessary and sufficient volume of molecular studies for the exhaustive detection of most epidemic genotypes of Mycobacterium tuberculosis in Russia and the countries of the former USSR.

Conclusions. Genetic lines L2 (Beijing) and L4 (Euro-American) cover more than 95% of all epidemic genotypes of M. tuberculosis in Russia and the countries of the former USSR. The development of rapid tests compatible with global data on genomic polymorphism will make it possible to conduct an epidemiological analysis of tuberculosis outbreaks within the country and to differ from cases of transbordern transmission of new genotypes outside.

Relevance. H. influenzae is a common cause of bacterial meningitis in children worldwide. Significant data have been accumulated worldwide on the use of H. influenzae type b conjugate vaccines over the past three decades. In the Russian Federation, constant monitoring of hemophilic meningitis is carried out, but data on the incidence of hemophilic infection are limited.

Target. To consider global changes in the epidemiology of invasive forms of H. influenzae in the world and in the Russian Federation.

Conclusions. The use of conjugate vaccines has resulted in a steady decline in invasive Hib infections. However, there has been a significant increase in invasive infections with non-typeable H. influenzae and non-b serotypes. In the Russian Federation, the incidence of meningitis caused by H. influenzae does not tend to increase or decrease; the majority of cases occur in children under 5 years of age.

Tularemia is a natural focal infection, characterized by the ability to maintain epizootic and epidemic potential for decades and periodically become more active. Since 2016, an increase in the incidence of tularemia has been observed in the Republic of Karelia.

Aims. To evaluate the epidemiological situation with tularemia in the Republic of Karelia to determine the directions of preventive work in modern conditions.

Conclusions. Analysis of the epizootic and epidemiological situation regarding tularemia in the Republic of Karelia demonstrates the possibility of intensifying the epizootic process after decades of relative prosperity. The increase in the incidence of the population was not only the result of the activation of natural foci of infection, but also of improved diagnosis of the disease and change in tactics for using vaccines in areas enzootic for tularemia.

The article discusses the limitations of the protective potential of the immune system associated with the peculiarities of the evolutionary mechanisms of the emergence of protein diversity and the late emergence in the evolution of the adaptive immune system, as well as problems associated with the formation of immunity to viral infections and immune collisions during vaccination. Using the example of hemagglutinin of the H1N1 influenza virus and S protein of the SARS-Cov-2 coronavirus, the features of the amino acid composition of their immunodominant (NA1 and S1) and subdominant (NA2 and S2) subunits are illustrated and the possibility of creating a universal vaccine against influenza viruses is analyzed. The principle of a new method for detecting linear peptide immunoepitopes recognized by MHC I and II and biomarkers of long-term immunity in surface viral proteins used as vaccines is described. The model of proteolysis of vaccine proteins in immunoprotesomes and lysosomes, features of the amino acid composition of surface proteins of viruses to which vaccines cause long-term immunity, and viruses to which vaccines have not yet been developed, as well as possible collisions with mRNA vaccines are examined. Possible collisions with mRNA vaccines are also being considered in connection with the identification of gene encoding limitations.