Relevance. In 2021, the World Health Assembly called on WHO Member States to strengthen the role of genomic epidemiological surveillance.
Objective. To present a revolutionary range of technological tools that determine the success of genomic epidemiological surveillance.
Results and discussion. Approaches that can take genomic epidemiological surveillance to a new technological level include rapid nucleic acid amplification methods, including isothermal amplification methods, metagenomic and targeted analysis using high-throughput sequencing technologies, a targeted genome editing system, as well as diagnostic solutions based on it, and the development of genomic sequence databases. In addition, it is necessary to note the importance of developing and implementing a comprehensive approach to the implementation of the genomic epidemiological surveillance system, taking into account the rapid development of a number of fundamental biological sciences related to epidemiology, as well as the wide application of information technologies in the processing of large data sets. Conclusion. Global trends confidently demonstrate a reduction in the time it takes for a technology to transition from scientific development to widespread practical application necessary to protect the population in the context of an epidemic spread of infections caused by previously unknown pathogens. For timely forecasting and prompt response to biological threats and ensuring sanitary and epidemiological well-being, the Russian Federation has successfully applied a triad of technologies: genomic epidemiological surveillance, mobile technologies and big data analytics. The authors consider biotechnological areas and technologies, the improvement of which will ensure the technological leadership of the Russian Federation in the field of genomic epidemiological surveillance.

Relevance. Seroepidemiological studies aimed at assessing population immunity are a powerful tool for epidemiological surveillance, necessary for analyzing and predicting the epidemic situation in a country, the actual protection of various age and social groups from a particular infection, and monitoring the effectiveness of specific prevention programs. Despite the relative simplicity of serological testing, there are numerous issues related to the design of studies, systematic sampling biases, sensitivity and specificity of tests, and validation of results. To effectively solve the problems of monitoring and predicting the development of infections, including the so-called new and returning ones, adequate information support is required, the level of which is determined by the availability of a certified collection of biological material. In this regard, biobanks, which have been actively developing in most countries in recent years, are becoming an essential element of modern biomedical infrastructure.
Aim. To characterize the importance of human blood serum banks in the system of global monitoring of population immunity, evaluation of the effectiveness of vaccine prevention and adaptation of its strategy (or justification for correcting its strategy) in response to changes in the epidemiological situation.
Results and discussion. The National Association of Biobanks and Biobanking Specialists (NASBIO) has been established in Russia, whose activities are aimed at supporting the development and implementation of scientific and applied projects and programs using the resources and infrastructure of biobanks. Depending on the type of biomaterial and the directions of its subsequent use, biobanks are divided into nosooriented (research, clinical) and population-based, which play an important role in the system of prevention of infectious diseases. Using the infrastructure of the blood serum bank makes it possible to obtain information on the seroprevalence, effectiveness of specific prevention programs and the level of susceptibility of various age and social groups of the population to vaccine-controlled infections.
Conclusion. In the context of expanding the range of real and potential biological threats, the effective functioning of human blood serum banks creates additional opportunities for studying population immunity, contributing to an increase in the effectiveness of the seroepidemiological monitoring system for current infections among the population.

Relevance. The diverse serogroup composition of meningococcal pathogens circulating in different countries, the challenges in predicting serogroup prevalence, migration processes, and the active aerosol transmission mechanism of meningococcal infection necessitate the use of vaccines with the broadest possible serogroup coverage for effective prevention.
Aim. To evaluate the immunological efficacy and safety of the MENVAID® vaccine for the prevention of meningococcal infections caused by serogroups A, C, Y, W, and X in the Russian Federation.
Materials and Methods. The immunological efficacy and safety of the MENVAID® vaccine were assessed in a prospective, comparative, randomized, double-blind clinical trial with parallel groups involving adult volunteers aged 18 to 65 years. A total of 60 adult volunteers were randomized into two groups in a 1:1 ratio (Group I, n = 30; Group II, n = 30). The comparator vaccine was Menactra®.
Study Results. For all five serogroups included in the MENVAID® vaccine, both the primary and secondary immunogenicity endpoints in adults aged 18–60 years were met in comparison to the reference product (Difference ≤10 %, GMT ratios ≥0.5, respectively), confirming that the immunogenicity of MENVAID® is non-inferior to that of the comparator vaccine, Menactra®. Moreover, MENVAID® demonstrated significantly higher GMT levels for serogroups C, Y, and W compared to the comparator vaccine. In total, 132 adverse events (AEs) were reported during the study in adults, of which 124 were related to vaccine administration and were represented by local and systemic reactions: 66 AEs were recorded in Group I participants (220 %), and 58 AEs in Group II participants (193.3 %). No statistically significant difference in the number of AEs between the groups was observed. No serious adverse events (SAEs) were reported during the study.
Conclusion. The MENVAID® vaccine for the prevention of meningococcal infection caused by serogroups A, C, Y, W, and X demonstrated non-inferior efficacy and comparable safety to the comparator vaccine when administered to healthy individuals aged 18 to 60 years.

Relevance. The problem of pertussis infection remains relevant, since the epidemic process at the present stage continues to involve both unvaccinated young children, schoolchildren vaccinated against this infection with lost immunity, and adults with an unknown diagnosis of pertussis.
Aims. The problem of pertussis infection remains relevant, since at the present stage, both unvaccinated young children, as well as schoolchildren with lost immunity vaccinated against this infection, and adults with an unspecified diagnosis of pertussis continue to be involved in the epidemic process.
Material & Methods. The study used data from the epidemiological surveillance of whooping cough presented in the state reports «On the state of sanitary and epidemiological welfare of the population in the Yaroslavl region» of the Office of Rospotrebnadzor in the Yaroslavl region, in the Russian Federation, the federal statistical observation form No. 2 «Information on infectious and parasitic diseases» and the medical history of whooping cough patients hospitalized in the GUZ YAO Regional Clinical Infectious Diseases Hospital" in 2023.
Results. The data was processed using the MS Excel 2016 software. The significance of the mathematical model was tested using the Fisher criterion. To assess statistical reliability, a table of critical values of the Fisher criterion was used, the significance level was assumed to be α = 0.05.
Conclusions. In order to reduce the incidence of pertussis, it is necessary to increase the coverage and timeliness of immunization against whooping cough in children, make adjustments to the Regional Calendar of preventive vaccinations and improve health awareness work.

Relevance. Rotavirus infection dominates in the structure of acute intestinal infections and is the leading cause of mortality from diarrhea in children under 5 years of age in the world. Despite existing preventive measures, vaccination is recognized as one of the most effective measures to reduce morbidity and mortality from RVI. Vaccination coverage in the Russian Federation as a whole has remained extremely low in recent years to influence the epidemic process.
Goal. Тo assess the effectiveness of the implementation of the regional program of vaccination of children in the first year of life of the Republic of Buryatia against RVI.
Materials and methods. A retrospective analysis of the accounting and reporting documentation of the Infectious Diseases Hospital was carried out according to the data of forms 5 and 6 of the URPN for the Republic of Buryatia. The incidence data for 2014–2024, as well as vaccination data for 2020-2024 were studied.
Results. During the observation period from 2014 to 2024, there is a decrease in the incidence of acute intestinal infections, rotavirus infection (by 57 %) in the Republic of Buryatia; a decrease in the proportion of rotavirus infection in general and in the group of children from 0 to 2 years old (inclusive) in the structure of acute intestinal infection of established etiology, at the same time, the proportion of RVI among acute intestinal infections of established etiology (AIIEE) in children 3-6 years old, especially in the group of organized preschoolers, is growing. In the structure of RVI cases, there was a gradual shift in the proportion of cases among children from 0 to 2 years old (inclusive) to older age groups: from 3 to 14 years (inclusive) and adults. Vaccination of RVI at the regional level has been carried out since 2021 with a gradual increase in coverage from 17 % to 78 % in 2021–2024, respectively. With an increase in vaccination coverage of more than 70 % (in 2023–2024), there is a sharp decrease in the number of cases in two groups – 0–1 years and 1–2 years and with a continuing trend of an increase in the number of cases in the group of 3 to 6 years old children according to the analysis of 2024 data. Among hospitalized children from 0 to 6 years of age, 3.6 % were vaccinated against RVI, including 2.8 % who received a full course of vaccination. All vaccinated children had a mild course of the disease, with or without subfebrile fever, with bed days ranging from 4 to 6 days.
Conclusions. The data obtained demonstrate the high efficiency of the regional vaccine prophylaxis program with a significant impact on the rates of hospitalization of children and adults with acute rotavirus gastroenteritis (ARRGE) and confirmed the importance of a regional approach to vaccine prevention of this controlled infection. The experience of application of the regional program of vaccine prevention of rotavirus infection in the Republic of Buryatia with vaccination coverage of 78 % is considered as positive and can be recommended for implementation in other regions of the Russian Federation in order to reduce morbidity and hospitalization of children with RVI.

Relevance. Parenteral viral hepatitis B (HBV) and C (HCV) affect not only millions of people, but also healthcare workers due to professional contacts, which lead to the progression of liver pathology and a reduction in medical activity. Numerous studies have shown that patients with double infection are at greater risk of developing progressive liver disease, cirrhosis, and hepatocellular carcinoma compared to monoinfected patients.
Aim. To assess the characteristics of the spread of latent forms of hepatitis C monoinfection and hepatitis C and B coinfection among healthcare workers depending on age and medical specialty.
Materials and methods. A serological and epidemiological observational descriptive prospective study was conducted based on the analysis of the results of a study of 1,643 workers who were considered healthy and did not have documented HBV, HCV, from 3 inpatient and outpatient medical organizations in an area with an active course of epidemic processes. Employees who were initially vaccinated against HBV were 1,597 (97.2 %) people and 46 (2.8 %) people who were not vaccinated. Subjects are included in the study after receiving written consent. Antibody levels were assessed based on the аnti–HВsAg study using commercial ELISA kits "VectoHBsAg - antibodies" (Russia); the presence of antibodies to the nuclear antigen of hepatitis B virus (anti- НВс) by the HepaBest anti-HBc-IgG ELISA method (Russia); the presence of total antibodies to HCV-core and -NS by the ELISA method «HCV-AT Confirmatory» (Russia). Statistical processing and analysis of the research results were carried out using Microsoft Excel 2010 and Prism9 software (GraphPad, USA.
Results and discussion. For the period under review (2023-2024) In the structure of HCV cases, 5 % of the study sample (1,643) were young people (up to 44 years old), while elderly and middle-aged people (45-60 years old) were more susceptible to combined forms of HCV and HBV (1.7 %). In the structure of professional categories suffering from HCV, the main share belongs to the nursing staff - 45.1 % (p<0.001), and the shares of doctors and junior medical staff accounted for approximately 25 % of the total structure (p=0.999), which can be explained by the peculiarities of the HCV factor in the professional environment, namely more frequent It is the average medical staff who has contacts with the blood of patients. Among people with simultaneous positive biotests to the HCV and HBV nuclear antigen, the leading position was occupied by junior staff (nurses) – 35.7 %. The average age of this cohort is 52 years ±12.44 years, and 9 out of 10 people in this cohort are nurses who work in the same medical institution.
Conclusion. The analysis makes it possible to identify organizations at the place of suspected infection, identify ways and factors of transmission, take measures to eliminate violations of the anti-epidemic regime, leading to increased risks of infection, and thereby ensure the biosafety of working conditions for healthcare workers.

Introduction. The main measure to combat hepatitis C in the framework of its elimination plan is the “test and treat strategy”, as well as dissemination of knowledge on hepatitis C virus (HCV) infection among population. In order to raise awareness and increase the coverage with viral hepatitis testing, Central Research Institute of Epidemiology annually holds a social campaign dedicated to World Hepatitis Day, which is celebrated annually on July 28 (hereinafter referred to as the Campaign), when anyone can undergo a free testing of viral hepatitis markers. In 2023, as part of the Campaign, anyone interested could get tested for anti-HCV.
The aim of the study was to analyze the results of the campaign in the context of the frequency of detection of HCV infection markers, genetic diversity of HCV and participants' knowledge of hepatitis C.
Materials and methods. Total 1,763 people were tested during Campaign. Along with blood sampling, all participants were asked to take a survey in which they had to choose one of the answers to 8 questions about the transmission routes, risks of infection, and the possibility of curing hepatitis C. The screening test for anti-HCV was performed in the Architect analyzer. In order to assess the feasibility of reflex testing, HCV RNA and HCV viral load were tested in the serum samples unloaded from the analyzer after anti-HCV testing using kits manufactured by the Central Research Institute of Epidemiology. To determine the HCV genotype and assess the risk of cross-contamination during reflex testing, sequencing and Bayesian phylogenetic analysis of the HCV core/E1 sequences were performed.
Results. Anti-HCV were detected in 189 of 1763 (10.7 %; 95 % CI: 9.4–12.3 %) serum samples. HCV RNA was detected in 37 of 189 (19,6 %) anti-HCV reactive sera, all HCV RNA-reactive samples had signal to cut-off (S/CO) ratio for anti-HCV >3, except for one sample with S/CO = 2.76. The proportion of individuals with active HCV infection confirmed by HCV RNA detection was 2.1 % (37/1763; 95 % CI: 1.5–2.9 %) among the campaign participants. Among HCV genotypes, 1b (38 %) and 3a (44 %) prevailed; genotypes 1a, 2a, 2k and RF_2k/1b were also detected. With the exception of two genotype 1b sequences that clustered together, the identified HCV sequences were not similar, confirming the absence of cross-contamination during reflex HCV RNA testing. The maximum risk of a false-positive result for the detection of active HCV infection due to cross-contamination in reflex testing was calculated to be 0.2 % (3/1763; 95 % CI: 0.03–0.52 %). Medium or low levels of awareness of hepatitis C were demonstrated by 31.4 % of the campaign participants.
Conclusions. Analysis of the results of the campaign demonstrated its effectiveness as a measure to increase the coverage with hepatitis C diagnostics and a tool for assessing the people's knowledge of this infection. The data obtained confirm the low risks of obtaining a false-positive result when conducting reflex testing for hepatitis C, which indicates the possibility of using a single serum sample for accurate and effective completed diagnostics of hepatitis C.

Relevance. Due to its high mortality rate and the risk of widespread spread, Ebola virus (EV) disease remains a major global health problem. Of great importance is the study of the characteristics of asymptomatic forms of the disease, which occur with high frequency in endemic regions.
Aim. To retrospectively evaluate the characteristics of population immunity and some laboratory parameters in individuals who have suffered a latent form of the disease caused by the Ebola virus (EB).
Materials and methods. To determine the proportion of individuals who have specific antibodies to the Ebola virus, 1079 volunteers living in the Kindia prefecture of the Republic of Guinea were examined from August 2017 to July 2018. To further assess the clinical and laboratory characteristics of seropositive cases, the study group (immune individuals, n=58) were compared according to basic epidemiological, clinical and laboratory parameters with a comparison group (healthy volunteers, n = 121).
Results. The proportion of seropositive individuals from the study sample was 8.6%. Most of the individuals in the study group lived in the Kindia city setting. The largest number of seropositive cases was observed among older patients. Among immune individuals, there were higher relative values of blood lymphocytes and lower relative values of segmented neutrophils, and a statistically significant higher content of leukocytes in the urine. The values of the parameters of the biochemical blood test did not exceed the reference limits.
Conclusion. The characteristics of population immunity and clinical and laboratory signs of the disease caused by the Ebola virus in individuals from a separate endemic region have been established.

Relevance. Given the substantial prevalence of pregnancy loss (20-46 % of conceptions), there is an urgent need to establish risk-prediction models for miscarriage to facilitate targeted preventive interventions.
Aim. To identify predictors of miscarriage and to develop prognostic models of miscarriage development based on risk assessment.
Materials and methods. We conducted a case-control study involving 282 women: 152 cases of spontaneous pregnancy loss (≤21 weeks gestation) and 130 controls with term deliveries. The assessment protocol included: a standardized 77-item questionnaire, validated Russian version of the Perinatal Anxiety Screening Scale (PASS-R, 31 items). Laboratory analyses comprised: molecular biological methods: quantitative PCR analysis of vaginal microbiota, microbiological assays: oropharyngeal swabs with semi-quantitative microbial growth assessment, fecal bacteriological examination for dysbiosis. Statistical analysis was performed using R software (v4.3.1), incorporating: univariate and multivariate logistic regression, ROC curve analysis (AUC) for model performance evaluation.
Results and discussion. Multivariate analysis identified statistically significant predictors of pregnancy loss, enabling development of two predictive mathematical models with strong discriminatory capacity. Key risk factors included: socio-demographic predictors (maternal age ≥35 years (aOR = 11.1; 95 %CI:1.46–238; p = 0.043), leadership occupation (OR = 8.92; 95 %CI:2.93–31.6; p < 0.001). Protective factor: normal body mass index (18.6–25 kg/m2; OR = 0.03; 95 % CI:0.001–0.32; p = 0.008). Clinical-anamnestic factors: medically indicated abortion history (OR = 8.07; 95 % CI:1.50–55.8; p = 0.021), smoking during pregnancy (OR = 6.06; 95 % CI:1.45–33.4; p = 0.022). Microbiological markers: severe intestinal dysbiosis (OR = 9.51; 95 % CI:2.37–64.7; p = 0.005). The developed models demonstrated excellent predictive performance, with high sensitivity and specificity (AUC 0.86 and 0.79).
Conclusion. The developed pregnancy loss risk prediction models, incorporating comprehensive socio-demographic, clinical, and microbiological predictors, demonstrate high specificity for spontaneous abortion risk stratification (AUC 0.861 and 0.790). These models show potential for refinement, validation, and eventual clinical implementation.

Relevance. The study of additional organization of vaccination in the regions of the country is an important task, especially in the context of global challenges associated with infectious diseases.
Aim. To analyze the existing regional calendars of preventive vaccinations in the subjects of the Russian Federation.
Result. A number of Russian regions provide additional vaccination as part of regional preventive vaccination calendars. Some regions create additional programs or comprehensive plans to organize immunoprophylaxis.
Conclusion. Regional calendars of preventive vaccinations allow to adapt vaccination programs to modern conditions and can be considered as a tool oftransitional period of implementation of the strategy of development of immunoprophylaxis of infectious diseases for the period up to 2035, approved by the order of the Government of the Russian Federation from 29.03.2021 № 774-r in part by including additional vaccinations against vaccine-preventable infections, taking into account the epidemic situation and the presence of high-risk groups of infection in the region.

Tetanus, caused by the action of toxins produced by Clostridium tetani, remains a disease with high mortality.
Aims: based on publications and official sources, to present a description of the current epidemic situation with tetanus in the world, the organization of planned vaccination against the disease, its effectiveness and safety. The prevalence of C.tetani has a zonality determined by the climatic and geographical features of the areas, but the incidence rate of tetanus in the modern period is determined by the state of work on its vaccination. From 1980 to 2023, the number of tetanus cases in the world decreased by 5.3 times. In Russia in the middle of the last century, an average of about 800 cases were registered annually, in 2006-2023 - from 8 to 21 cases. The coverage of completed 3-doses vaccination of children in the world in 2018-2023 was 84-86 %, in our country it exceeded 96 %. The coverage of adults with vaccination in Russia exceeds 90 %, which is confirmed by the results of seromonitoring of collective immunity. National tetanus vaccination shchedule have some differences, not all countries carry out boosters doses of the adult population. Vaccines with different tetanus toxoid content are used to immunize children and adults, and post-vaccination complications after the use of vaccines containing tetanus toxoid are rarely recorded. Selective studies of tetanus seroprevalence in the population conducted in various countries, including some regions of Russia, have shown a high level of immune protection for children and adults. The proportion of people with a protective level of antitoxic antibodies to tetanus in different age groups was higher than to diphtheria. It was shown that antitoxic immunity to tetanus persists for over 10 years at a level higher than protective.
Conclusion: Decades of planned mass immunization of the world population against tetanus have shown its high epidemiological effectiveness and safety. Persons who have completed the vaccination course develop more intense and long-lasting antitoxic immunity than to diphtheria.

Relevance. Measles meets the criteria for a disease that can be eradicated. However, it has not yet been possible to achieve sustainable elimination of this infection, and the duration of post-vaccination measles immunity is becoming an important issue.
Aim. To present in a review based on current literature data the features of the immune response to vaccination against measles.
Conclusion. Understanding the characteristics of post-vaccination and post-infection immunity, and finding a way to maintain lifelong immunity in vaccinated individuals, is an important task in achieving the goal of eliminating measles. Elimination of measles is still achievable, it requires increasing the coverage of vaccination and studying the features of the individual immune response to maintain population immunity. Keywords: measles, vaccination, immune response, immunogenetics, MMR, seronegativity, antibodies, HLA.