Development, study, and comparison of models of cross-immunity to the influenza virus using statistical methods and machine learning.

Introduction: The World Health Organization considers the values of antibody titers in the hemagglutination inhibition assay as one of the most important criteria for assessing successful vaccination. Mathematical modeling of cross-immunity allows for identification on a real-time basis of new antigenic variants, which is of paramount importance for human health.

Materials And Methods: This study uses statistical methods and machine learning techniques from simple to complex: logistic regression model, random forest method, and gradient boosting.

Characteristics of self-regulation of the epidemic process of infection caused by the Epstein-Barr virus (Herpesviridae: , HHV-4).

Introduction: Among the available scientific literature, there are no publications addressing processes of self-regulation in the parasite-host population systems with reference to chronic infections, including the infection caused by the Epstein-Barr virus (EBV infection). The aim of the study is to assess manifestations of the epidemic process of chronic EBV infection through the lens of the basic tenets of the theory of self-regulation of parasitic systems.

Materials And Methods: The study was performed using data from scientific publications selected from such database sources as Scopus, Web of Science, Cochrane Library, PubMed, CyberLeninka, RSCI, etc.

Distribution of human gene polymorphisms allele frequencies associated with viral infections.

Introduction: The design of studies aimed at finding the association between the genetic factor and the studied feature (disease) involves a comparison of the ratio of genotypes or allelic proportions in the study group with those in the control group. At the stage of determining the ratio of genotypes of the studied polymorphisms in the reference group, researchers meet a number of problems, which are the subject of the present work. Aim of the work is to provide scientific rationale for the feasibility of creating a national information system comprising genetic data of the relatively healthy population of Russia, incorporating its ethnic diversity.

[Mathematical model for assessing the level of cross-immunity between strains of influenza virus subtype HN].

Introduction: The WHO regularly updates influenza vaccine recommendations to maximize their match with circulating strains. Nevertheless, the effectiveness of the influenza A vaccine, specifically its H3N2 component, has been low for several seasons. The aim of the study is to develop a mathematical model of cross-immunity based on the array of published WHO hemagglutination inhibition assay (HAI) data.

[Epstein-Barr viral infection is a global epidemiological problem].

The number of studies devoted to Epstein-Barr viral infection (EBV infection) has been growing in recent years. However, they all relate to the clinical aspects of this problem. Epidemiology issues remain practically unexplored.

[Identification by enzyme immunoassay of escape mutants S143L and G145R of hepatitis B virus ()].

Introduction: The achievement of the goal of the World Health Organization to eliminate viral hepatitis B by 2030 seems to be problematic partly due to the presence of escape mutants of its etiological agent, hepatitis B virus (HBV) (<i>Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus</i>), that are spreading mainly in the risk groups. Specific routine diagnostic assays aimed at identification of HBV escape mutants do not exist.The study aimed the evaluation of the serological fingerprinting method adapted for routine detection of escape mutations in 143 and 145 aa positions of HBV surface antigen (HBsAg).

[Modern views on the role of X gene of the hepatitis B virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus) in the pathogenesis of the infection it causes].

The review presents information on the role of hepatitis B virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus) (HBV) X gene and the protein it encodes (X protein) in the pathogenesis of viral hepatitis B. The evolution of HBV from primordial to the modern version of hepadnaviruses (Hepadnaviridae), is outlined as a process that began about 407 million years ago and continues to the present. The results of scientific works of foreign researchers on the variety of the influence of X protein on the infectious process and its role in the mechanisms of carcinogenesis are summarized.

Recombinant HBsAg of the Wild-Type and the G145R Escape Mutant, included in the New Multivalent Vaccine against Hepatitis B Virus, Dramatically Differ in their Effects on Leukocytes from Healthy Donors In Vitro.

Immune-escape hepatitis B virus (HBV) mutants play an important role in HBV spread. Recently, the multivalent vaccine Bubo-Unigep has been developed to protect against both wild-type HBV and the most significant G145R mutant. Here, we compared the effects of recombinant HBsAg antigens, wild-type and mutated at G145R, both included in the new vaccine, on activation of a human high-density culture of peripheral blood mononuclear cells (PBMC) in vitro.

Detection of S-HBsAg Mutations in Patients with Hematologic Malignancies.

Multiple studies of hepatitis B virus (HBV) genetic variability and its relationship with the disease pathogenesis are currently ongoing, stemming from growing evidence of the clinical significance of HBV mutations. It is becoming increasingly evident that patients with hematologic malignancies may be particularly prone to a higher frequency of such mutations. The present report is the first extensive study of the prevalence of escape mutations in S-HBsAg, performed using isolates from 59 patients from hospital hematology departments with diagnoses of leukemia (n = 32), lymphoma (n = 20), multiple myeloma (n = 3), and non-tumor blood diseases (n = 4).

[Reactivation of Epstein-Barr virus (, HHV-4) infection during COVID-19: epidemiological features].

Introduction: Immunodeficiency underlying the development of severe forms of new coronavirus infection may be the result of mixed infection with SARS-CoV-2 and other pathogens, including Epstein-Barr virus (EBV).The aim is to study the prevalence and epidemiological features of co-infection with SARS-CoV-2 and EBV.

Material And Methods: A cross-sectional randomized study was conducted in Moscow region from March to May 2020.

[Patterns of the SARS-CoV-2 epidemic spread in a megacity].

Unlabelled: The purpose of the study is to analyze patterns demonstrated by the COVID-19 epidemic process in a megacity during the increase, stabilization and reduction in the incidence, and to evaluate the effectiveness of the epidemic prevention measures.

Materials And Methods: The comprehensive study incorporating epidemiological, molecular genetic and  statistical research methods was conducted to analyze the spread of SARS-CoV-2 in Moscow during the COVID- 19 pandemic.

Results And Discussion: It was found that the exponential growth in COVID-19 cases was prevented due to the most stringent control and restrictive measures deployed in Moscow to break the chains of SARS-CoV-2 transmission and due to people who were very disciplined in complying with the self-isolation rules.

National Association of Biobanks and Biobanking Specialists: New Community for Promoting Biobanking Ideas and Projects in Russia.

The research biobanking field is developing rapidly in Russia. Over the course of the last decade, numerous biobanks were created or formed from existing collections of human and environmental biospecimens. The Russian National Association of Biobanks and Biobanking Specialists (NASBIO) was established in December 2018, aiming to: (1) unite professionals and research centers to create and develop a network of biobanks in Russia; (2) provide services and expertise in the field of biobanking; (3) execute various research projects utilizing biobanks' infrastructure; and (4) facilitate integration of Russian biomedical research centers into global research activities.

[Viral hepatitis B, C and infectious mononucleosis: epidemiological similarities and differences.].

Introduction: The presence of etiologically unencrypted diagnoses in the structure of viral hepatitis determines the relevance of searching for other pathogens involved in liver pathology formation. The role of Epstein-Barr virus in the development of hepatitis was described in the scientific literature, but official statistics do not allow to assess its contribution to liver damage along with hepatitis B and C viruses. The purpose - to identify common and distinctive epidemiological features of viral hepatitis B (HB), C (HC) and infectious mononucleosis (IM).

[Detection of Epstein-Barr virus genome in oral cavity squamous cell carcinoma samples of russian patients.].

Introduction: Oral cavity squamous cell carcinoma (OC-SCC) is the most common and aggressive malignancy of the oral cavity. Recent studies have revealed infections with human papilloma virus (HPV) as an additional risk factor for oral squamous cell carcinoma development, while distinguished role of Epstein-Barr virus (EBV) remains still uncertain. However, the evidence for association between virus infection and risk of oral squamous cell carcinoma is controversially and varies significantly by geographic regions and race.

[The role of Epstein-Barr viral infection and hepatitis B and C in liver pathology.].

A review of scientific literature data on clinical and epidemiological characterization of viral hepatitis B, C and Epstein-Barr viral infection is presented. Scopus, Web of Science, MedLine, The Cochrane Library, PubMed, CyberLeninka, RSCI databases were used to find the necessary literature. It was shown that Epstein-Barr virus along with hepatitis B and C viruses plays a significant role in the development of virus-mediated autoimmune liver diseases, as well as other organs (intestine, heart, kidneys, thyroid gland, etc.

MORPHOLOGICAL ANALYSIS OF HEPATITIS B VIRUS WITH ESCAPE MUTATIONS IN S-gene G145R AND S143L.

Background: In terms of serological properties and immunization, the wild type of HBsAg HBV and its G145R mutant behave as different antigens. This testifies to serious structural changes, which presumably could have a significant impact on the morphogenesis of virions and subviral particles. Nevertheless, morphological and ultrastructural investigations of HBV with G145R mutation have not been carried yet.

[A comparative characteristic of antigenic properties of recombinant and native hbs-antigens with G145R mutation and evaluation of their immunogenicity].

Background: One of the important reasons for spreading of hepatitis B virus (HBV) under conditions of vaccinepressure is emergence of escape mutations. Prevalent G145R mutation in S-gene leads to the most expressed changes of serological properties of HBV. Consequently, HBsAg is modifed so thoroughly that it cannot be recognized by the majority of anti-HBs.

[IMMUNOPATHOGENESIS OF OCCULT INFECTION CAUSED BY HEPATITIS B VIRUS].

The concept of occult infection caused by hepatitis B virus (HBV) is determined as the presence of HBV DNA in blood sera or liver with the absence of detectable HBsAg. The actuality of this problem is associated with the fact, that occult hepatitis B (OHB) can be transmitted during hemotransfusions, cause reactivation of chronic hepatitis B in immune compromised individuals, facilitate development of liver cirrhosis and hepatocellular carcinoma. Several different hypotheses of OHB immunopathogenesis have been proposed, including a low number of copies of HBV DNA, altered immune response of the macroorganism, genetic variability of the S gene, integration of viral DNA into host genome, infection of mononuclear cells of peripheral blood, presence of immune complexes that hide HBsAg, and interference by other viruses such as HCV and HIV.

[EFFECTIVENESS OF PREVENTIVE VACCINE PROPHYLAXIS OF CHICKEN POX IN MILITARY COLLECTIVES].

Aim: Study the effectiveness of preventive vaccine prophylaxis of chicken pox in military collectives.

Materials And Methods: In the focus of chicken pox, 200 servicemen of the new addition by conscription were immunized once against chicken pox; 97 servicemen by conscription of the new addition (comparison group) were not vaccinated. Epidemiologic and immunologic effectiveness of conduction of preventive vaccine prophylaxis in chicken pox focus were studied.

[Search for RNA of the hepatitis E virus autochthonous for Russia in the most likely infection sources].

The research carried out for 30 years from the moment of hepatitis E virus (HEV) discovery has proved the presence of the autochthonous HEV in non-endemic areas: Europe and Russia. Monitoring of the HEV antibodies (anti-HEV) among the Russian population has revealed regions with increased seroprevalence that testifies to high probability of local HEV infection in these areas. Contact with HEV can represent special danger for patients of the risk groups.

[Problems of diagnosis of the hepatitis B virus].

The recent data on the genetic variability of the hepatitis B virus and problems of serological ELISA-mediated detection of this virus are discussed.

[Hepatitis E: current concepts].

Hepatitis E belongs to the group of enetral hepatites. Its earlier cases caused by genotype I and II viruses were reported largely from epidemics affecting tropical and subtropical countries. Sporadic cases of hepatitis E recorded later in West Europe, North America, Southeast Asia, and Oceania were caused by genotype III and IV viruses.

[Actual problems of creation of informational-analytical system for rapid control of epidemics of infectious diseases].

Structure and modules of computer informational-analytical system "Electronic atlas of Russia" is presented, the object of mapping in this system is epidemiology of socially significant infectious diseases. Systemic information on processes of emergence and spread of socially significant infectious diseases (anthroponoses, zoonoses and sapronoses) in the population of Russian Federation is presented in the atlas. Detailed electronic maps of country territory filled with prognosis-analytical information created by using technological achievements of mathematic and computer modeling of epidemics and outbreaks of viral and bacterial infections are of particular interest.

[Banks of biological resources in the system of basic epidemiological and clinical studies].

Banks of biological resources appear to become the key centres of long-standing international scientific infrastructure necessary for efficacious use of achievements in public health. Approaches to building up the global system of monitoring socially significant and other dangerous infections based on the passported blood sera bank and computerized epidemiological database meeting the current WHO standards are discussed. An innovative project for the creation of the Electronic Atlas of Russia is considered that must provide an original information-analytical system for the study of the most widespread infectious diseases with the use of modern geoinformation technologies.