Relevance. The genetic recombination between viruses and men is known long ago. It can be divided on relict and ontogenic ones. For the host the recombination may display different consequences the nature of which is not exposed explicitly.

Aim is to analyze (on the base of computer comparison of the primary structure of viral and human proteins ) the occurrence of twodirectional recombination by small genome fragments between viruses and men and describe its possible after-effects.

Materials and methods. For this computer study human and virus protein sequences were used from data bases available in INTERNET.

Results. It was indicated that recombination (cryptical and explicit) by small genome fragments between viruses and men occurred many times in the past and many viruses pathogenic for men were involved in it.

Conclusion. The bioinformatics approach allows to look at the past of viruses and men and find the traces of genetic information changes between them that may predetermine the effects of vaccines and diagnostic immune tests.

Relevance. Influenza is characterized by global distribution and the difference in its seasonality in countries with temperate and tropical climates. The importance of studying antigenic variation of influenza viruses due to the fact that changes in the antigenic structure is an evolutionary mechanism of adaptation of the virus to ensure its survival and cause annual epidemics.

Aims. The Aim of this study was to identify the peculiarities of the geographical spread of influenza (seasonal), etiology and the rate of antigenic variability of influenza viruses A and B.

Materials and methods. Based on data from WHO Reference research centers, information was collected on circulating influenza virus strains from 1975 A(H3N2), 1977 A(H1N1)pdm09 and type B of the Yamagata and Victoria lines from 1987 to 2019, as well as data on the number of all identified influenza viruses and individual strains circulating in the Northern and Southern hemispheres from 2008 to 2018.

Results and discussion. Analysis of the global spread of influenza, its etiology and antigenic variability of viruses, according to WHO, showed that the influenza A(H1N1)pdm09 virus was the main causative agent of epidemics and regional outbreaks in seasons of high influenza activity in all countries except the United States and Canada, where influenza A(H3N2) and B viruses dominated in countries with severe seasonality, the change of season led to a change in the etiology of influenza, and in tropical countries, the A(H1N1)pdm09 virus more often remained dominant in all seasons of the year.

Conclusions. The pronounced seasonality of influenza in Northern countries and its absence in tropical countries, where regional outbreaks prevailed in all seasons of the year, were confirmed. Low antigenic variability of influenza A(H1N1)pdm09 strains was confirmed, and the highest – A(H3N2). Among influenza B strains in the Victoria line had less antigenic variability, because the duration of its circulation before the appearance of a new drift variant was longer than that of the Yamagata line. The tendency to increase the total duration of circulation of influenza viruses B/Victoria, A(H1N1)pdm09 and B/Yamagata due to increased circulation before the emergence of new drift variants is shown.

Background. The study of immune memory is necessary to evaluate the effectiveness of immunization against infection, including plague and to make a choice of vaccination scheme.

Goals. The goal is to study the possible role of immune memory in the early stage of the antigen-specific response – the formation of cells with receptors for capsular (F1) and lipopolysaccharide (LPS) antigens of plague live EV vaccine.

Methodology. Volunteers vaccinated with live plague vaccine EV for the first time (6 persons – group 1) and again (6 persons – group 2) were examined. In the mononuclear fraction of the blood of volunteers the cells binding antigens F1 and LPS Y. pestis (CBA) were determined.

Results. In the volunteers group 2, the content of CBA at 2 days after vaccination was higher than in group 1. Between the 5th day and the end of the CBA detection, their content in group 2 decreased, and in group 1, it increased, but remained significantly less than in group 2 two days after immunization.

Сonclusions. It is shown that the previous vaccination accelerates the first stage of the antigen-specific human response to second vaccination against plague. This reflects the role of immune memory in the formation of this stage of the immune response at vaccination against plague.

Relevance. The increase in the frequency of infections caused by Pseudomonas aeruginosa and Acinetobacter baumannii, which have a high level of resistance to many groups of antibiotics, requires a comprehensive study, including modern research methods.

Aims. The study of regional features of the dynamics of the formation and circulation of antibiotic-resistant strains A. baumannii and P. aeruginosa.

Materials and methods. During 2009-2018 we analyzed the data of microbiological laboratories of multidisciplinary hospitals and carried out a molecular genetic study of the determinants of antibiotic resistance by PCR of A. baumannii and P. aeruginosa strains isolated from clinical material in order to determine the level of variability of resistance.

Results. The study revealed a tendency to increase in the proportion of strains A. baumannii and P. aeruginosa in the etiological structure of healh-care associated infections and purulent-septic infections; high incidence of strains resistant to cephalosporins, carbapenems, beta-lactams and multi-resistant strains. The appearance and distribution of the determinants of antibiotic resistance NDM-1 and MCR-1 in these bacteria were also detected.

Conclusions. Over the past decade, a steady increase in the proportion of A. baumannii and P. Aeruginosa resistant to many antibiotics in patients in intensive care unit and surgery departments in hospitals of Vladivostok (Primorsky reg., Russia), and the emergence of new antimicrobial resistance mechanisms in these microorganisms.

Relevance. Vaccination of people at high risk against pneumococcal infection with a 13-valent conjugate vaccine (PCV13) can significantly reduce the corresponding incidence and mortality.

The aim of the work was to assess the pharmacoeconomic aspects of vaccination of 65 year olds with a high risk of pneumococcal infection.

Material and methods. The analysis was carried out by the method of Markov modeling from the position of the health care system. The time horizon is 5 and 15 years. It was assumed that vaccination is carried out with 1 dose of PCV13 and 1 dose of polysaccharide pneumococcal vaccine (PPV23) after 8 weeks with revaccination with 1 dose of PPV23 after 5 years. The costs of treatment of pneumococcal infections were calculated on the basis of the Compulsory medical insurance rates for St. Petersburg in 2019. The costs of vaccination were calculated on the basis of the price of auctions for the purchase of PCV13 and PPV23 for 2019.

Results. For 15 years, vaccination of 100 ths people from the high risk group will prevent 1.7 ths cases of community-acquired pneumonia, 1.4 ths cases of invasive pneumococcal infections, and 397 cases of pneumococcal infections deaths. The cost-effectiveness ratio with a 15-year horizon is 161.4 ths rubles/quality-adjusted life year gained (QALY). Even if the time horizon is reduced to 5 years, vaccination can be considered as an economically highly effective intervention (cost-effectiveness ratio –571.9 ths rubles/QALY). At the same time, in 5 years, 37.6% of the money spent on vaccination will be returned to the budget of the health care system, and in 15 years – 49.3%.

Conclusion. Vaccination of citizens of the Russian Federation from a high-risk group against pneumococcal infection can be considered as a socially and economically highly effective intervention that provides a significant reduction in the incidence and mortality caused by it.

Relevance. The absence of a registered vaccine against G145R escape mutant determines the need to develop a drug for the prophylaxis of infectious hepatitis caused by the hepatitis B virus.

The aim of the study was to evaluate the safety and reactogenicity of a new hepatitis B recombinant Bubo®-Unigep yeast vaccine in healthy volunteers.

Materials & Methods. To confirm the safety of the new trivalent Bubo®-Unigep vaccine, an open, single- center, nonrandomized clinical trial was conducted in healthy male volunteers at the clinical base of «Uromed» (Smolensk) according to the protocol developed by the contract research organization R&D Pharma.

Results and discussions. Safety and reactogenicity assessment was carried out throughout the study period. In the safety assessment, one adverse event was reported that was not related to the use of Bubo®-Unigep vaccine. No serious adverse events have been reported. There were no local reactions at the injection site throughout the observation period. The results indicate a high safety and areactogenicity of Bubo®-Unigep vaccine.

Conclusions: The confirmed safety and areactogenicity of a new Bubo®-Unigep vaccine in a phase I clinical trial allows to proceed to the next stage and to conduct a registration study in which immunogenicity, safety and reactogenicity will be studied during the full course of vaccination. The introduction of such a vaccine on the market will contribute to a more effective vaccination against those serotypes of the hepatitis B virus that are endemic and prevail in the Russian Federation. Due to the created complete immunity, the infection threshold rises and the number of cases of hepatitis B among the already vaccinated population decreases.

Background. The study of regional characteristics of the incidence rates of perinatal mortality, early neonatal mortality, and stillbirths is of undoubted importance, which will allow to substantiate the main directions of improving care for newborns, both at the federal and regional levels.

Aims. To study the indicators of perinatal mortality, early neonatal mortality and stillbirths in the territory of the Nizhny Novgorod region in the period from 2012–2016.

Materials and methods. Statistical reporting forms of the Ministry of Health of the Nizhny Novgorod region «Basic indicators of public health and the activities of state medical organizations of the Nizhny Novgorod region» for the period from 2012 to 2016. A retrospective descriptive-estimated epidemiological study of perinatal and early neonatal mortality rates and stillbirth rates was conducted. The processing of statistical indicators was carried out by generally accepted methods of variation statistics. The reliability of the indicators was estimated taking into account the confidence interval (2 errors with 95% CI).

Results and conclusions. On the territory of the Nizhny Novgorod region in the period from 2012 to 2016. A high level of perinatal mortality and stillbirths was observed compared to the national indicators. The average annual rates of perinatal mortality and stillbirth were significantly higher in Diveevsky and Sokolsky districts compared with the rest of the Nizhny Novgorod region. The risk areas for neonatal mortality include Lukoyanovsky and Tonkin. It is necessary to improve the quality of medical care for pregnant women at all stages, including prenatal and, of course, obstetric care. An important role here is played by the improvement of the epidemiological surveillance system, which allows an objective analysis of the current situation and an assessment of the quality of medical care.

Relevance. Acute intestinal infections still retain their social and medical significance in the world, with a reduction in the incidence of well-studied bacterial infections, such as salmonellosis and, especially, shigellosis.

Discussion. Since 2006, the incidence of bacterial dysentery in Russia has continued to decrease, in the Republic of Dagestan it is at a high level, exceeding more than 10 times the national average. Mostly children are sick (up to 75%). Cases of shigellosis are recorded throughout the year, the seasonal increase in the incidence in the summer and autumn is associated with the activity of the main transmission pathogens – water and food. The main causes of epidemiological well-being for schigеllosis in Dagestan are determined by: poor state of the water supply system and sanitary and communal improvement of populated areas; the use of food products stored, transported and sold in the distribution network in violation of sanitary and hygienic requirements. So, in 2017 and 2018 – 67.1% and 32.69% of drinking water samples of water pipelines did not meet hygienic standards, respectively, in terms of sanitary and chemical indicators, 53.1% and 65.6% of water pipelines did not meet the requirements of sanitary legislation. The flare incidence, which is recorded annually, indicates the activity of the epidemic process of acute intestinal infections and shigellosis in the republic. The experience of various territories of the country, including those affected by adverse environmental and climatic phenomena (floods, floods, flooding), shows high efficiency along with traditional measures aimed at breaking the transmission mechanism of the pathogen, Shigellosis vaccine prophylaxis. In Dagestan, vaccination is limited, mainly in foci, where bacteriophage polyvalent dysentery S. sonnei and S. flexneri 1, 2, 3, 4, and 6 serotypes are used more widely for prevention and treatment. In this situation, the optimization of the system of epidemiological surveillance of shigellosis, which consists in improving the pre-epidemic diagnosis and epidemiological monitoring of measures aimed at each link in the epidemic process, including the creation of immunity to pathogens in individual population groups due to specific prevention, is of particular relevance to the Republic.

Conclusion. The constant flare incidence of dysentery dictates the need, along with traditional measures to interrupt the transmission of the pathogen, to carry out vaccine prophylaxis more widely in risk groups. Potential sources of shigella have formed in the republic; there is a potentially high risk of the mechanism of transmission of the pathogen, as well as the population potentially susceptible to the pathogen, indicating the presence of such a danger and the need for its comprehensive study as an object of risk-oriented surveillance. Thus, the key directions in improving the surveillance of shigеllosis in the Dagestan Republic should be pre-epidemic diagnosis in a risk-based epidemiological surveillance system. The introduction of modern sensitive, specific, standardized methods of laboratory diagnostics will make it possible to effectively carry out risk-oriented epidemiological surveillance, which makes it possible to identify the transition of risk factors from potential to real, activating the epidemic process.

Subject. Varicella continues to be a common childhood infection, but thereof danger is underestimated in our country and around the world. About 800 thousand people get sick every year in the Russian Federation, half of whom are children 3–6 years old. In addition, for economic damage from infectious and parasitic diseases, varicella in the Russian Federation occupies 2–3 place for eleven years.

Objectives. To substantiate the need to introduce varicella vaccine into the National immunization schedule of the Russian Federation based on the experience of introducing vaccination into regional schedules.

Materials and Methods. The descriptive epidemiological method was used – a retrospective epidemiological analysis. Materials for the study were: Form № 2 «Information about infectious and parasitic diseases» for 2007–2017; State reports «On the state of sanitary and epidemiological welfare of the population in the Russian Federation» for 2016, 2017; scientific publications on the studied issue in Russian and English. The program «Microsoft Excel» was used to process the research data. Results. In regions in which varicella vaccination is introduced into regional immunization schedules, the incidence of infection tends to decrease at least to 3,1%, in contrast to regions where it is not introduced and there the incidence is increasing every year to 2,8%. The experience of using mass vaccination in other countries has shown its effectiveness, what is observed by decrease the incidence to a sporadic level.

Discussion. The incidence of varicella in 2017 by region of the Russian Federation, where vaccination is included into regional immunization schedule, is 75% lower than the national average. Analysis of varicella vaccination introduction experience in other countries clearly shows that this method of combating varicella can significantly reduce the incidence, as well as reduce economic damage (US – 0.9 billion dollars, Japan – 36.2 billion yen).

Conclusion. The vaccine prophylaxis of varicella clearly shows that this method of combating this infection can significantly reduce the incidence and at times reduce the economic damage from infection. With this in mind, the need to consider the inclusion of varicella vaccination in the Russian Federation National Schedule of Vaccinations.

Aim. Present the current state of the incidence of mumps in the Russian Federation.

Conclusions. The current epidemic situation of mumps in the Russian Federation is characterized by a predominance in the age structure of the incidence of adolescents and young working age people and determines the need to develop and introduce in medical activity a standard definition of the clinical case of mumps for correct verification of the diagnosis with subsequent laboratory confirmation. The emergence of the phenomenon of «growing up» of mumps and the registration of periodic outbreaks in the long-term practice of vaccination dictates the need to improve further vaccination prevention tactics with an emphasis on the adult population as part of the implementation of the National preventive vaccination calendar.

Along with the theoretical concepts and definitions of risk adopted in the epidemiological analysis of infectious diseases, the identification of «risk areas» is of great importance.

The aim is to show the role of risk factors when determining the «risk areas» and in the genesis of complications of the epidemiological situation. Taking into account the multifactorial nature of the epidemic process under infectious diseases, we describe the risks used in zoning of natural focal particularly dangerous (plague, tularemia, anthrax, Ebola virus disease, Yellow fever); arbovirus (Crimean-Congo haemorrhagic fever, West Nile Fever and anthroponotic (cholera and other acute enteric infection (AEI) of norovirus, rotavirus and enterovirus etiology) infections. The importance of risk factors and conditions for their implementation in AEI with water pathogen distribution (unsatisfactory state of water supply and water use, population migration, etc.) and emergencies, in which certain risk factors can contribute to the complication of the epidemic situation, is shown.

Conclusion. The use of risk factors in zoning of administrative territories is aimed at improving epidemiological surveillance. It is possible that potential risk factors can transfer to real, what results in activation of the epidemic process.

Relevance. Vaccination against the tick-borne encephalitis (TBE), during the mass immunization, by using modern vaccines provides high epidemiological effect (98–99%); however, there are known cases of incidents among vaccinated population. The problem of incidents among vaccinated population is insufficiently studied, likewise a reliability of the diagnostic, vaccination conditions and causes of vaccinated people’s morbidity.

Purpose of the article generalization of the information about morbidity among the vaccinated population.

Conclusions. The review for the first time provides information about the main issues of this problem: the frequency of illness of vaccinated people in Russia (by federal districts and individual regions), disease development conditions, tied up with vaccination regimens and types of vaccines, clinical features and diagnosis of the disease of vaccinated people. Particular attention is paid to the state of post-vaccination immunity. The significance of two phenomena is being studied: incomplete neutralization of the virus, which leads to the formation of a fraction of a free infectious virus; and the phenomenon of the hyperimmunization with the development of immunological tolerance.

Relevance. Cervical cancer (CC) continues to be the focus of attention of oncologists all over the world due to the fact that the incidence of it over the past decades has not tended to decrease. The steady increase in morbidity, high mortality rates, and the tendency to «rejuvenate» the disease, the relatively low detection rate of the early stages of the disease due to poor results of cytological screening predetermine the search for new scientifically based approaches to solving cervical cancer problems. A promising direction for the prevention of squamous cell carcinoma and adenocarcinoma associated with human papillomavirus (HPV) is prophylactic vaccination against HPV, the need for which is due to the role of HPV infection in carcinogenesis processes.

The aim of this article is to summarize the currently available data on advances in the prevention of precancerous lesions and cervical cancer, primarily through vaccination against HPV infection.

Conclusions. The creation of vaccines for the prevention of oncogenic HPV types is a significant achievement in the biomedical research area. The successful development of a group of vaccines, which can confidently be called the vaccines of the 21st century, gives us hope that modern medicine has the potential to reduce population cancer risk and reduce the likelihood of early onset of cervical cancer. Demonstration of the efficacy and feasibility of routine HPV vaccination programs in a number of countries demonstrates encouraging progress in solving cervical cancer problems. Vaccination against HPV will not only ensure epidemiological well-being, but also lead to a decrease in morbidity and mortality from such a terrible complication of human papillomavirus infection – cervical cancer.