Relevance. Vaccines are regarded as an effective means for control of the Covid-19 pandemic spreading and their search, analysis, and comparison of their features are important for elucidating the most safe and effective one.

Aim. At the end of 2020 two types of vaccines (viral based vaccines and mRNA vaccines) have been licensed to vaccinate. The aim is to compare their features for objective substantiation of their application.

Conclusions. As both vaccine types have high effectiveness in inducing antibodies to SARS-Cov-2 (in more 90% recipients) the utility of each vaccine type in blocking the Covid-19 pandemic spreading is beyond doubt. In both vaccine types eventually S protein is the antigen source, and they have limitations for vaccination. In comparison with the vector vaccines mRNA vaccines may induce serious complications, have the least potential to induce trained immunity and can be included into the recipient’s genome. The low frequency of influenza cases in the current epidemic season serves as an of interference between SARS-Cov-2 and influenza viruses. In epidemic seasons after the Covid-19 pandemic coronaviruses may dominate amongst viruses inducing acute respiratory viruses diseases. It is likely that the decline of the Covid-19 case count (in December-January) in Russia is determined by the heterologous collective immunity formed earlier.

Relevance In the context of the new coronavirus infection (COVID-19) pandemic, research on the formation of an immune response to SARS-CoV-2 in patients with various clinical forms of this infection is of particular relevance, which is important for understanding the degree of their participation in the formation of population immunity and assessing individual immunity to SARS-CoV-2 in the future.

Aim of the study was to analyze the timing of the formation of specific antibodies to SARS-CoV-2 and the duration of their preservation in patients with a new coronavirus infection.

Materials and methods. The timing of the formation of specific antibodies of three classes (IgA, IgM and IgG) to SARS-CoV-2 in 218 patients was evaluated in the first days of the disease. Subsequently, they were re-examined at various times from the onset of the disease, from one to four times (a total of 321 control points). To assess the duration of preservation of antibodies to COVID-19 in patients who were ill, a prospective study was organized, in which 368 people participated. Screening for specific class G antibodies was performed every 2–4 weeks, within one to eight months of the onset of clinical manifestations of COVID-19. In total 919 control points. The antibodies were examined by solid-phase enzyme immunoassay using the SARS-CoV-2IgM-ELISA-BEST and SARS-CoV-2-IgG-ELISA-BEST test systems (manufactured by VECTOR-BEST JSC) and Antigma A (manufactured by Generium).

Results. In most of the examined individuals, class M and G antibodies began to form from day 10 of the disease, while class A antibodies were detected from day 5. In mild and asymptomatic forms of coronavirus infection, IgG antibodies to SARS-CoV-2 were not formed in most cases, and seroprotection levels correlated with the severity of the disease. The duration of preservation of IgG antibodies could be at least 8 months, but there were isolated cases of their elimination both after COVID-19 in the form of respiratory infection and after interstitial pneumonia. With continuing problems with COVID-19, there were no cases of recurrent disease among individuals who formed G-antibodies (including those who lost them 4-5 months after the disease) during the follow-up period.

Conclusion. Thus, according to the results of the study, important materials were obtained on the peculiarities of the formation of a humoral immune response to a new coronavirus infection. However, to fully understand the immune response to SARS-CoV-2, it is necessary to assess the avidity of IgG antibodies or their ability to neutralizing the virus, as well as to study cellular immunity in patients who have had COVID-19 but have not formed antibodies.

Relevance. At the children's oncological hospital guidelines to treat patients with several groups of antibiotics at the same time, which ensures the formation of multi-resistant strains of Clostridium difficile, which have a selective advantage for the Clostridium difficile infection developing, and also cause epidemics and /or in associating with an increase in the severity of Clostridium difficile – infection.

Aims. Multidrug resistance Clostridium difficile strains and Clostridium difficile infection rate at pediatric oncological hospital.

Results. An investigation of the Clostridium difficile resistance strains carried out among children at the children's oncological hospital. 143 toxigenic strains are resistant to moxifloxacin 72.41%, clindamycin 63.72%, rifampicin 35.54%, tetracycline 26.45%, tigecycline 11.42%, vancomycin 4.4%, metronidazole 3.9%. At the same time, the increase multidrug-resistant strains proportion note at the level of 3–4% per year. However, the rate of Clostridium difficile infection among children at the oncological hospital remained at the level of 0.4% to 3.1% with a downward trend. As a result, statistical calculations showed the absence of correlation between multidrug resistance and morbidity.

Conclusions. Detection of multidrug-resistant microorganisms among toxigenic Clostridium difficile strains proves the need for further study of this problem in Russia and the advisability of monitoring Clostridium difficile infection rate and multidrug resistance Clostridium difficile strains at pediatric oncological hospitals.

Relevanc. Measles, mumps and rubella, despite many years of vaccination, retain their epidemiological and social significance at the present time.

The aim of the work is to study the safety and immunogenicity. Of the vaccine for the prevention of measles, rubella and mumps Vactrivir® in children's immunization.

Materials and methods. The safety and immunogenicity of the vaccine was studied in a simple multicenter blind comparative randomized clinical trial involving children aged 12 months and 6 years.

Results. The Vactrivir® vaccine is characterized by low reactogenicity, a high safety and immunogenicity profile and is comparable in terms of indicators to the foreign Priorix® vaccine, which has been used in the Russian Federation for specific prevention of measles, rubella and mumps since 2018.

Relevance. Staphylococci are one of the most common pathogens in the etiological structure of nosocomial infections. Methicillinresistant staphylococci are resistant to the main groups of antibiotics and are one of bacteria that pose the greatest threat to human health according to the World Health Organization. The introduction of modern molecular biological methods in the monitoring of methicillin-resistant staphylococci is necessary for the rapid and accurate identification of microorganisms, monitoring the epidemiological situation and studying the need for anti-epidemic measures. Aims. Аnalysis of the results of monitoring methicillinresistant staphylococcus strains using molecular biological methods in a multidisciplinary hospital in Moscow for one year.

Materials and methods. Single-center observational study with a one-year follow-up period (December 2016 to December 2017). The research included a molecular-biological analysis of biological material from 240 patients with signs of infection and washings samples (n=250) from the objects of the hospital environment. The whole genome sequencing was carried out for 24 samples, isolated from patients with different forms of staphylococcal infection and washings from a hospital environment. DNA detection of methicillin-resistant strains was performed using the «AmpliSens®MRSA-screen-titer-FL» reagent kit. Sequencing was performed on an Illumina HiSeq1500 instrument using the IlluminaHiSeq PE RapidClusterKit v2 and IlluminaHiSeqRapid SBS Kit v2.

Results. DNA of methicillin-resistant staphylococci were detected in 6.3% of blood samples from patients with signs of infection and in 42.4% of washings from the objects of the hospital environment. The results of PCR of washing samples showed that DNA of methicillin-resistant coagulase-negative staphylococci were detected much more often than MRSA (p <0.001). DNA of methicillin-resistant staphylococci were detected more often in the intensive care and intensive care units compared with the hematology and surgical departments (p <0.001). The examine samples of Staphylococcus aureus belonged to 6 different sequence types (ST-5, ST-7, ST-8, ST-22, ST-30 and ST-5555) and 8 spatypes (t008, t021, t091, t1062, t12437, t1544, t223, t4573). As a result of monitoring, an isolate with a new allelic profile was found. Today it has been assigned the number ST5555. The predominant type of staphylococcal mec cassette was the type IV SCCmec cassette.

Conclusion. Due to the widespread distribution of methicillin-resistant strains and the identification of epidemiologically significant genetic lines of staphylococci, it is necessary to conduct regular monitoring, take measures to limit the spread of such strains and introduce modern molecular biological methods for quick and accurate identification.

Relevance. Natural and climatic conditions, a variety of species composition of arthropods and vertebrates determine the possibility of circulation of arboviruses in the Volgograd region. The existence of natural foci of some arbovirus infections and the possibility of the formation of others suggests the need for annual monitoring of the causative agents of arbovirus diseases.

Аim. Evaluation of the results of monitoring of arbovirus infections in the Volgograd region in 2019.

Materials and methods: 806 blood serum samples from donors, 44 blood serum samples from febrile sick people, 300 blood serum samples from horses and 94 pools of blood-sucking mosquitoes were examined by immunofernal analysis. Result of the study of serum samples from donors in the Volgograd region, in 140 (17.4%) of 806 were found to have antibodies to the pathogen of West Nile fever (in 35 (4.3%) – IgM, in 105 (13.0%) – IgG), in 7 (2.2%) of 319 – to the Crimean hemorrhagic fever virus (in 4 (1.3%) – IgM, in 3 (0.9%) –IgG), and in 7 (2.9%) of 240 – IgG to the viruses of the California serogroup. Specific antibodies against viruses of Sindbis, Batai and Uukuniemi in the samples was not detected. The largest number of positive samples with the presence of IgG and IgM to the West Nile virus was found among residents of Volgograd (61 out of 240, 25.4%) and Volzhsky (25 out of 100, 25, 0%). Among 44 blood serums of febrile patients, 1 sample (2.3%) was found to contain an antigen of the Sindbis virus, and 2 samples (4.5%) – antigens California serogroup viruses. Specific immunoglobulins against West Nile virus were detected in 84 (28%) of 300 blood serums of farm animals (horses). In the study of 94 samples of field material (blood-sucking mosquitoes), West Nile virus antigen was detected in 14 (14.9%), Sindbis virus – in one sample (1.0%), Batai virus – in four samples (4.2%).

 Conclusions: the obtained results, along with the circulation of West Nile virus and Crimean hemorrhagic fever virus virus in the Volgograd region, indicate the presence of Sindbis, Batai and California serogroup viruses and necessitate further study of their role in the infectious pathology of the population.

Relevance. There are large regional disparities in prevalence of non-communicable disease risk factors, as well as in the cardiovascular disease (CVD) incidence and mortality rates in Russian Federation (RF). Aim. To demonstrate the disparities in prevalence of CVD risk factors between Vologda Oblast districts.

Materials and methods. Databases created in 2009 at the State-financed health institution of the Vologda Oblast «Vologda Regional Center for Medical Prevention», based on the results of a survey conducted within the framework of the World Health Organization CINDI program. CINDI questionnaire; cross-sectional study; the data was processed using R programming language and the Statistica software package 12.

Results. The most common behavioral CVD risk factors in different Vologda Oblast districts included inadequate fruits and vegetables consumption (30–90%) and alcohol abuse (40–80%); hypertension (40–60%), overweight and obesity (30–55%) were the most frequent biological CVD risk factors; the most prevalent socio-economic risk factors included low education level (75–90%) and unemployment (20–40%). Participants residing in rural municipalities differed from urban okrugs (cities) dwellers in a higher prevalence of smoking (p < 0.01), alcohol abuse (p < 0.001), inadequate fruits and vegetables consumption (p < 0.0001), overweight and obesity (p < 0.05), unemployment (p < 0.0001), low education level (p < 0.0001), as well as a low overall assessment of their health (p < 0.05).

Conclusions. We detected disparities in CVD risk factors prevalence between Vologda Oblast districts in 2009. Both behavioral and biological CVD risk factors were more common in participants from rural municipalities. The CVD risk factors distribution between the RF subjects’ districts requires further scientific research.

Influenza remains one of the most pressing medical and socio-economic problems . Vaccination is the most effective way to reduce the incidence and mortality of influenza and its complications.

Рurpose: estimate the awareness of parents , doctors of various specialties and students of the medical University about the issues of influenza vaccination, identify factors that affect the reduction of vaccination adherence and determine the best apt ways to increase adherence to influenza immunoprophylaxis.

Methods. A descriptive retrospective epidemiological study between 2004 and 2018 Conducted a survey among three groups of respondents: parents of children enrolled in the children's clinic or treated at a pediatric hospital (n=1620); doctors of different specialties (n = 324); the medical students (n = 433).

Resalts. Against the background of increasing coverage of the population with preventive vaccinations, there is a decrease in the incidence of influenza among the total population (TPR.=-14.7%). There was a weak correlation between the number of vaccinated and the incidence in the following year (ρ =-0.38 p>0.05). Only 22.2% of respondents vaccinate a child, and only adults are vaccinated in 13.8% of cases. Among doctors of different specialties, 36.7% are vaccinated against the flu, and 58.7% of respondents additionally vaccinate their children against the flu. Of the total number of students surveyed, 17.3% are vaccinated annually.

Conclusions. Increasing adherence to flu vaccination among medical students and doctors will help increase adherence to vaccination among the population, increase coverage of preventive vaccinations, and reduce the incidence of influenza.

Relevance. The worldwide use of pneumococcal vaccines, in particular conjugated vaccines (PCV), has led to a significant reduction in the incidence of invasive pneumococcal diseases in both vaccinated children and unvaccinated people of all ages. However, "non-vaccine" serotypes and capsule-free (non-typed) strains have become the main causes of pneumococcal disease, as with carriage, with an increase in antibiotic resistance. This requires new approaches in the development of vaccines that can lead to serotype-independent protection, especially in children, the elderly and immunocompromised people. The pneumococcal vaccine should protect against a wide range of serotypes, induce mucosal and systemic immunity, and reduce primary nasal colonization, as well as invasive forms.

Aim. The review is devoted to the analysis of experimental development of innovative vaccines based on protective protein antigens (PPV), including in combination with capsular polysaccharides, using adjuvants or antigen delivery systems, as well as inactivated whole cell preparations (WCV) and live attenuated vaccines. Particular attention is paid to the methods of mucosal immunization, taking into account the tropism of pneumococcus in relation to the mucous membranes of the upper and lower respiratory tract.

Conclusion. At this stage, the most developed and promising are drugs based on bacterial lysates (PWCV) and protective protein antigens (PspA, dPly), as well as these antigens mixed with adjuvants, and, possibly, with some etiologically most significant capsular polysaccharides.

Relevance. Recently, there has been an increase in the incidence of head and neck cancer throughout. Head and neck cancer is one of the most common forms of cancer, accounting for 5-10% of all cancers in the world. In the structure of cancer it takes 8th place.

Aim. Highlight the main risk factors for the development of malignant neoplasms of the head and the etiological role of the human papillomavirus.

Conclusions. Currently, it is an increase in prevalence of viral infections is considered to be the main cause of increase in the incidence of squamous cell carcinoma of the head and neck, and this pathology is more common among non-smoking middleaged man with a high socio-economic status, having oral-genital sex with multiple sexual partners, as well as having poor dental status.

Relevance. Against the background of epidemiological well-being for diphtheria infection, the formation of the optimal structure of the population post-vaccination antitoxic immunity remains an urgent problem.

Aims. The review is devoted to anti-toxic antidiphtheria immunity and the possibility to form the optimal structure of post-vaccination anti-toxic population immunity using the small booster doses of anatoxin.

Results. Special attention is paid to the formation of antitoxic population immunity in a natural way during the pre-vaccination period. It is proposed to pay attention to the immunosuppressive characteristics of anatoxin and the immune response to booster its small doses. Natural decrease in the concentration indicators of post-vaccination antitoxic IgG in the blood of adults has been demonstrated. A mathematical analysis of determining the structure of post-vaccination population immunity in all age groups of the population is proposed.

Conclusions. The small booster personalized doses of anatoxin in adolescents and adults will contribute to the creation of optimal population anti-diphtheria protection of these age groups of the population.

Relevance. Vaccine prophylaxis is the most cost-effective and affordable means of controlling infectious diseases. At the same time, there is a great regional diversity in the number of people who refuse vaccination. In our country, according to several large studies, there is a relatively low adherence to vaccination compared to other European countries. It is common to have doubts and questions about immunization in adult patients or parents who vaccinate their children. A decrease in vaccination coverage of the population can lead to an increase in the incidence of infections preventable by immunization. At the same time, measures to promote vaccination used by preventive health care systems in various countries are insufficient. This increases the likelihood for doctors of various specialties to meet in their daily activities with patients' questions and concerns about vaccination

.The purpose of this work was to highlight the practical aspects of building a dialogue with patients who have doubts about vaccination.

Conclusions. Successful communication is based on the doctor's ability to build a confidential dialogue based on confidence in the decency and goodwill of all its participants. Based on the study, the following conclusions can be drawn. An alarming trend in recent years is the increasing number of patients who doubt the effectiveness of vaccination. For hesitant patients, the doctor is one of the most important sources of information about vaccines. The doctor's ability to clearly and confidently build a dialogue about vaccination helps to dispel the patient's doubts and is the most effective means of increasing adherence to immunization of the population.