During the COVID-19 (Corona Virus Disease 2019) pandemic, the world medical community has done a tremendous job to find effective treatment and methods for preventing the disease. The experience accumulated earlier in the fight against COVID-19 (MERS, SARS-CoV, etc.) has made it possible in the shortest possible time to develop a long-awaited method for the specific prevention of COVID-19, based on a large number of effective and safe vaccines against SARS-CoV-2, which were adopted society is ambiguous. Fear of high contagiousness and mortality from COVID-19 has been replaced by anxiety about the need and benefits of vaccination. The abundance and easy accessibility of information, as well as the contradictory points of view in various sources of non-professional information, gave rise to new misconceptions and provided resources for the actions of dissident movements.
This paper provides a generalized analysis of the results of the vaccination campaign against COVID-19, examines the factors that influence the success of achieving population immunity. Particular attention is paid to social and psychological barriers among the population that prevent the widespread use of vaccines against COVID-19, the COVID dissident movement, the manipulative beliefs of the anti-vaccination community that can affect the implementation of preventive measures against the disease.

The COVID-19 pandemic has been going on for more than a year and a half, and the number of confirmed cases of infection in the world has already exceeded 150 million people. The multisystemic nature of the lesions in COVID-19, as well as the Post-COVID- 19 syndrome, has been proven, which requires a rethinking of the rehabilitation of such patients. This lecture discusses current approaches to medical rehabilitation in patients with COVID-19 from the view of an infectious disease specialist and a pulmonologist. Methods and exercises of respiratory rehabilitation, including early ones, are indicated in detail. The directions of pharmacological and dietary support of rehabilitation, as well as vaccination after COVID-19 in the aspect of rehabilitation are presented. The directions of studying the human respiratory microbiome in the context of rehabilitation after COVID-19 are proposed.

The aim of the study was to assess the seroprevalence to the SARS-CoV-2 nucleocapsid in the population of the Nizhny Novgorod region against the background of COVID-19.
Materials and methods. The work was carried out according to a unified methodology developed by Rospotrebnadzor with the participation of the St. Pasteur. The selection of volunteers for the study was carried out by the method of questioning and randomization. The exclusion criterion was active COVID-19 infection at the time of the survey. A total of 2829 volunteers were surveyed, divided into seven age groups. Venous blood samples were taken from all volunteers from EDTA vacutainers. In the blood plasma, the content of specific IgG to the SARS-CoV-2 nucleocapsid was determined by the enzyme immunoassay.
Results. The population level of immunity to SARS-CoV-2 among the surveyed volunteers was 8,4% (95% CI 7,4–9,5). The largest proportion of seroprevalent persons was found among children aged 1–6 years — 15,9% (95% CI 8,2–26,7), the smallest in the group of volunteers aged 18–29 years — 6,0% (95% CI 3,8–8,9). During 3-stage serological monitoring, the proportion of seroprevalent volunteers increased to 22,5% (95% CI 20,3–24,9)%, or almost 2 times from the initial level (p<0,05). of the population of the Semenovsky district (22,7% (95% CI 10,9–41,8)), the smallest — in the city of Dzerzhinsk (2,4% (95% CI 0,5–7,1)%) Among convalescents after COVID-19, specific antibodies were detected in 47,2% (95% CI 30,5–69,6), which is 5,6 times higher than the average for the population. Among those who had verified contact with patients, specific IgG were detected in 17,6% (95% CI 12,9–23,5), which is 2,1 times higher than the average for the population. Among asymptomatic persons who had a positive PCR result, 53,3% (95% CI 30,5–86,6) were seropositive, which is 6,3 times higher than the average for the population. Of 225 seropositive people, 188 (88,4% (95% CI 76,6–101,6)) had the disease asymptomatic.
Conclusion. The relatively low proportion of seroprevalent persons among the population may indicate a significant risk of further development of the epidemic process caused by COVID-19 in the territory of the Nizhny Novgorod region.

The objective. To assess the dynamics of the epidemic process of chronic hepatitis C (CHC) in Russia and the Northwest Federal Region for the period 2015–2020.
Materials and methods. The article analyzes the data from the state statistical reporting of infectious diseases in the Russian Federation (RF), from the reference-center for the monitoring of viral hepatitis, from statistical tables compiled at Methodological and Research Center for Epidemiological Surveillance of Viral Hepatitis under Pasteur Institute of Epidemiology and Microbiology. The data from the Federal register of patients with viral hepatitis were used.
Results. The epidemiological indicators for 2020 should be interpreted taking into account the implementation of anti-epidemic measures for COVID-19 in the context of a pandemic. In 2015–2019, CHC incidence in the RF decreased by 18% (from 38^o⁄_oooo to 30,9^o⁄_oooo). For 2020 — by 46% (up to 16,7^o⁄_oooo). The total number of people with CHC is increasing (in 2015 — 562 622 people, in 2019 — 635 372). There is no clear downward trend in the dynamics of changes in the mortality rate from causes associated with HCV in the RF and the Northwestern Federal Region. The impact of the pandemic on mortality in HCV infection remains to be assessed. In 2019 in Russia, only 8,6% of patients on the register are covered by treatment. In 2020, according to preliminary data, treatment coverage was less than 1% of the estimated number of people with HCV infection (3 million). СHC incidence in the Northwest Federal Region decreased by less than 15% (48^o⁄_oooo — in 2019, 56,2^o⁄_oooo — in 2015), for 2020 — by 41% (up to 28,2^o⁄_oooo). Incidence is 1,5 times higher than in the RF on average. The total number of people with СHC is increasing (in 2015 — 92 780, in 2020 — 106 052). Few people with viral hepatitis know about their diagnosis (35% HCV-infected persons). Government funding for treatment has increased, but only 3% is covered by therapy. In the Northwestern Federal Region, as in the RF, the WHO strategy targets have not been achieved by 2020. The sharp decline in basic epidemiological indicators for 2020 is most likely due to a decrease in the number of patients seeking outpatient care and screening during the implementation of anti-epidemic measures for COVID-19.

Objective: to assess mitochondrial parameters in CD4+ T-cells of HIV/HCV coinfected patients with a discordant and standard response of the immune system to antiretroviral therapy.
Materials and methods. HIV/HCV coinfected patients with discordant (n=21) and standard (n=20) response to treatment were examined. The control group comprised of 23 uninfected volunteers. In CD4+ T-cells, PGC-1a content, mitochondrial mass, and mitochondrial membrane potential were determined with flow cytometry.
Results. In CD4+ T-cells of HIV/HCV coinfected subjects with standard and discordant response to treatment, mitochondrial membrane potential was similar to that of uninfected donors. Compared with healthy controls, HIV/HCV coinfected patients had increased organelles’ mass and PGC-1a expression in CD4+ T-cells. In contrast to healthy individuals, HIV/HCV coinfected subjects had no correlation between mitochondrial mass and PGC-1a content in CD4+ T-lymphocytes.
Conclusion. In CD4+ T-cells of HIV/HCV coinfected patients with discordant and standard response to antiretroviral therapy, up-regulation of mitochondrial mass is not associated with energy production. In HIV/HCV coinfection, there is no relationship between the mitochondrial mass and mitochondrial biogenesis regulator.

The goal is to conduct a comparative analysis of the characteristics of blood counts of pregnant women with HIV living in the subarctic climatic zone of the Khanty-Mansiysk District, as predictors of a systemic inflammatory reaction on the background of infection and pregnancy complicated by preterm delivery.
Material and methods. A retrospective analysis of 78 stories of pregnant women with HIV (main group II) was carried out, in 2016–2018. observed in one antenatal clinic in the city of Surgut. Control group (I) comprised 20 histories of pregnant women without HIV. Clinical-anamnestic and blood parameters were compared, including indicators of T-helpers, T-suppressors and viral load, leukocyte intoxication indices, hemoglobin, erythrocytes and platelets by trimesters of pregnancy. The material was processed using the Statistica-10 software system. The critical level of statistical significance was taken at p<0,05.
Results. A comparative analysis of blood counts of pregnant women living in the subarctic region showed a relationship between the preterm labor of patients with HIV with a progressive decrease in the T-cell level of immunity, an increase in the level of lymphocytes and leukocyte blood indices, a decrease of hemoglobin, erythrocytes, platelets, against the background of persisting viral load for the remainder of pregnancy. A decrease of T-lymphocyte counts indicates the development of a systemic inflammatory response on the background of HIV infection, depletion of the immune defense organs and the progression of the disease, while a low level of CD4 lymphocytes stimulates the activation of granulocytes in the blood and indicates further depletion of T-lymphocytes. Activation of a systemic inflammatory response that promotes the release of inflammatory mediators and prostaglandins and, with a high probability, underlies the mechanisms of rejection of the fetus and placenta and the spontaneous preterm labor. The comorbid background of pregnant women with HIV and preterm labor is associated with low adherence to HAART therapy and high detectable viral load throughout gestation.

Introduction. In most cases, HIV infection in children is accompanied by the development of anemia.
Objective: to study the nature of the disturbance of the cellular composition of blood in HIV-infected children on the background of antiretroviral therapy.
Materials and methods. In the period from September 2015 to January 2017, 124 patients aged from 0 to 18 years old were examined with a diagnosis of HIV infection at various stages of its development. In all patients in the peripheral blood, the hemoglobin concentration, the absolute number of red blood cells, leukocytes and their varieties in a blood volume unit were determined, the hematocrit value was calculated.
Results and discussion. Against the background of ongoing antiretroviral therapy, the formation of hypochromic anemia is associated with a consistent decrease in hemoglobin concentration and the number of circulating red blood cells to 104,86±2,80 g/l and to 3,81–3,67×10¹²/l, which may be accompanied by a decrease in their content in each erythrocyte and the appearance of macrocytic erythroid forms in circulating blood. Leukopenia develops due to the formation of an absolute deficiency of circulating lymphocytes and neutrophilic granulocytes.
Conclusion. The specific assessment of cytopenia depends on the type of primary damage to the blood cells, and the choice of specific treatment depends on the type of disorder. Therefore, timely correction of these disorders could possibly reduce the development of the immunodeficiency state.

Antibodies with neutralizing activity against a wide range of human immunodeficiency virus 1 subtypes (known as broadly neutralizing antibodies (bNAb)) are of great interest as a therapeutic agent for the treatment of HIV infection, because they are able to provide natural protection against most HIV-1 strains. The review discusses the mechanisms of formation of bNAbs, their classification by binding to conservative regions of the envelope protein, as well as their intrinsic features. Description of the most promising bNAbs and their combinations is presented. In the last section the results of clinical trials available to date are reviewed in detail.

Antibodies with neutralizing activity against a wide range of human immunodeficiency virus 1 subtypes (known as broadly neutralizing antibodies — bNAb) are of great interest as a therapeutic agent for the treatment of HIV infection, because they are able to provide natural protection against most HIV-1 strains. The review discusses the mechanisms of formation of bNAbs, their classification by binding to conservative regions of the envelope protein, as well as their intrinsic features. Description of the most promising bNAbs and their combinations is presented.
In the last section the results of clinical trials of 3BNC117, VRC01 and 10-1074 bNAbs available to date are reviewed in detail. An important finding of these studies was that the introduction of a single antibody is followed by the appearance of resistant viral variants. The investigation of the only combination of 3BNC117 and 10-1074 completed so far indicates that combined therapy is more effective and allows to achieve long-term viral suppression in some patients. The promise of combined HIV immunotherapy is evidenced by the initiation of a large number of clinical trials evaluating the efficacy of two or more different bNAbs.

The aim of this study was to characterize the genetic variants of HBV currently circulating in the Republic of Guinea, based on the nucleotide sequences of the complete virus genome, and to analyze clinically significant mutations in the Core and HBsAg regions during HBV monoinfection and HBV/HIV coinfection.
Materials and methods. The study material was represented by 2616 blood serum samples collected from residents of the Republic of Guinea. The subjects were examined for the presence of HBV markers with a qualitative detection of HBsAg, HBs IgG, and HBCore IgG. HBV complete genome nucleotide sequences were obtained for 298 samples including HIV/HBV coinfected patients. Amplification and subsequent sequencing of HBV were performed using nested PCR with pair’s overlapping primers jointly flanking the complete HBV genome (S, P, C, X genes).
Results. HBV serological markers were detected in 80.77% samples, while HBsAg was detected in 16.01% of the examined group. HBV DNA we detected in 22.36%. The prevalence of HBsAg-negative HBV in patients with HIV RNA is 45.16%, which is significantly higher than 6.07% found in the group without HIV infection. Phylogenetic analysis of HBV in the examined samples showed that HBV genotype E (75.5%) predominates in the group compared to HBV genotype D1 (9.39%), D2 (4.02%), D3 (6.37%), and A2 (4.7%). In the tested group, the variability of amino acids among the HBV samples was higher in the PreCore/Core region than in the PreS1/PreS2/S region. SHB mutations were detected in 83,89%, Core mutations in 94.29%, PreCore amino acid substitutions in 16.77% of the patients, respectively.
The results obtained in this work demonstrate a high prevalence of HBV in the region and indicate the need for further largescale studies of HBV mutations in order to improve strategies for disease control and prevention in the Republic of Guinea.

Data describing the effects of ultrasound upon biological objects of blood serum is analyzed in the paper. Biophysical as well as medical aspects of tissue reactions caused by ultrasound are considered in fine detail including the immune complexes’ dissociation processes accompanied by releasing of antibodies and antigens that used to be present in bound form and have been inaccessible for revelation by means of laboratory tests. The prospects of using ultrasonic techniques in laboratory diagnostics are presented using HIV-infection as an example.