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Objective was to investigate the SARS-CoV-2 collective immunity status of the population of Belarus within the context of the COVID-19 pandemic. Materials and methods. The work was carried out according to the methodology for assessing SARS-CoV-2 population immunity, developed by Rospotrebnadzor Russia and the Ministry of Health of Belarus with the participation of the St. Petersburg Pasteur Institute, taking into account WHO recommendations. The Bioethics Committee of Belarus and the local ethics committee of the St. Petersburg Pasteur Institute approved the study. Selection of participants was carried out using a questionnaire method and online technology (internet, cloud server). Volunteers were randomized into seven age groups (years of age): 1–17; 18–29; 30–39; 40–49; 50–59; 60–69; and 70+. Regional randomization ensured proportional representation of volunteers from each region, and no more than 30 people were included from one enterprise. In accordance with manufacturer instructions, blood plasma samples were analyzed for: IgG antibodies (Abs) to the SARS-CoV-2 nucleocapsid (Nc) using a quantitative ELISA test system; and IgG Abs to the receptor binding domain (RBD) of the SARS-CoV-2 S (spike) surface glycoprotein using a qualitative ELISA test system. Statistical processing was carried out using Excel 2010 and other software. Statistical differences were designated as significant when p 0.05, unless otherwise indicated. Results. The level of seroprevalence, in terms of Abs to Nc among the Belarusian population, was 38.4% (95% CI 37.6–45.4). The highest Ab levels were found among individuals in older age groups (50-70+ years old). The lowest were found in children 1–17 years old and in young people 18–39 years old The distribution of seroprevalence across Belarusian regions was relatively homogeneous, with the exception of the Minsk Region, where a statistically significant decrease in the indicator was noted. In terms of profession, the largest share of seropositive individuals was found among transportation workers; the smallest was found in business. The moderate COVID-19 incidence has not led to a dramatic increase in the number of contacts. The base reproduction number (R0) was 1.3. In the Republic of Belarus, there was a moderate level of asymptomatic COVID-19 among seropositive individuals (45.3% [95% CI 44.0–46.7]). This form of infection was observed most often among children aged 1–17 years old (65.0% [95% CI 61.3–68.6]). In parallel with seroprevalence assessment, SARS-CoV-2 vaccination was carried out. We used two vaccines: Gam-COVID-Vac (also known as Sputnik V, developed by Gamaleya National Center for Epidemiology and Microbiology, Russia); and BBIBP-CorV (Sinopharm, PRC). Vaccination against SARS-CoV-2 was accompanied by an increase in the level of anti-RBD Abs (95% [95% CI 94.7–96.7]). Taking into account the vaccination of a subset of the population with BBIBP-CorV, the overall herd immunity, inferred from the analyzed indicators (presence of anti-Nc or anti-RBD Abs), was 47.1% (95% CI 46.3–48.0). Conclusion. COVID-19 in Belarus was characterized by a moderately pronounced course of the epidemic process. The threshold level of herd immunity to SARS-CoV-2 has not yet been reached, as a result of which the conditions for progression of the epidemic remain.

Aim. To determine the level of SARS-CoV-2 seroprevalence among the Novosibirsk Region population against the background of the COVID-19 pandemic.Material and methods. The work was carried out in 2 phases: 1) a cross-sectional cohort study performed 28.06– 15.07.2020; 2) longitudinal cohort 3-stage seromonitoring: 1st stage 28.06–15.07.2020; 2nd 14.09–04.10.2020; 3rd 10–30.12.2020 The work was carried out according to a unified methodology developed by Rospotrebnadzor with the participation of St-Petersburg Pasteur Institute, taking into account the recommendations of the WHO. IgG antibodies to the SARS-CoV-2 nucleocapsid protein were detected by ELISA using a kit of reagents produced by the SRCMSB (Obolensk) according to the manufacturer’s instructions. Statistical analysis was performed using Microsoft Excel 2010 and other programs.Results. The seroprevalence in the region’s population was 9.1% (95% CI 8.0–10.2): maximum in children 14–17 years old (17.6%, 95% CI 12.3–23.9) and persons over 75 years (14.8%, 95% CI 11.4–18.8), minimum among persons 30–39 years old (4.9%, 95% CI 3.0–8.0). Increased rate was noted among the unemployed (15.4%, 95% CI 9.9–17.1) and other individuals (13.0%, 95% CI 8.6–18.5). Seroprevalence was 33.3% (95% CI 16.3–59.0) in COVID-19 convalescents and 19.0% (95% CI 13.9-25.0) in contact persons. More than 94.7% (95% CI 91.2–97.2) of seropositive individuals were asymptomatic. During the serological monitoring, seroprevalence increased from 7.4% (95% CI 6.2–8.9) at 1st stage 1 to 12.4% (95% CI 10.6–14.3) at 2nd , and 31% (95% CI 28.8–33.3) at 3rd stage.Conclusion. SARS-CoV-2 herd immunity has not reached the threshold level, this does not exclude exacerbation of the epidemic process.

On account of the COVID-19 pandemic, the global pharmaceutical industry has achieved impressive results in the development and introduction of various types of vaccines causing the formation of acquired immunity against the SARS-CoV-2 coronavirus into clinical practice. However, none of them currently show the declared one hundred percent guarantee of protection. In the case of the COVID-19 disease, patients with concomitant pathologies are the most vulnerable to the occurrence of severe complications. The aerosol route of transmission of SARS-CoV-2 contributes to the emergence of outbreaks of the new coronavirus infection in crowded places and closed rooms with poor ventilation. In this regard, an urgent problem is the search for drugs with local antiviral activity, which, together with restrictive measures and mask wearing policy, can potentially reduce the likelihood of contracting coronavirus. In this experimental in vitro study on Vero CCL81 cell culture (ATCC), the local antiviral activity of the drug Thymogen® spray against the SARS-CoV-2 virus was studied in comparison with the antiseptic Miramistin® solution. As a result of the experiment, no toxic effects on Vero cells were detected in the drugs in the studied concentrations. In a series of experiments, Thymogen® spray showed local antiviral activity against SARS-CoV-2 when the virus titer was 5,2 lg TCID50. Therefore, the drug Thymogen® dosed nasal spray has high potential as a topical drug for prevention and treatment of COVID-19 disease, which requires additional confirmation in relevant clinical studies.

Purpose. Determination of the SARS-CoV-2 population humoral immunity among the population of the Krasnoyarsk Territory during the COVID-19 epidemic.Materials and methods. The study was carried out as a part of project for assessing population immunity to SARS-CoV-2 among the population of Russian Federation using unified methodology developed by Rospotrebnadzor, with the participation of the Research Institute for Epidemiology and Microbiology named by Pasteur, and taking into account the recommendations of the WHO. The work involved 2907 volunteers, selected by the online survey and randomization by age and territory. All volunteers were divided into 7 age groups: 1–17, 18–29, 30–39, 40–49, 50–59, 60–69, 70 and older (70+), including a total 246–449 people. Population immunity testing was carried out during the formation of groups (1st stage), and then twice more, with the interval of 6–8 weeks. Serum was obtained from venous blood samples obtained from volunteers, in which antibodies to the SARS-CoV-2 nucleocapsid were determined by the enzyme immunoassay. The results were analyzed by methods of nonparametric statistics: median, interquartile range, rank correlation coefficient were calculated in the Excel statistical package. The confidence interval to seroprevalence indicators (95% CI) was calculated using the WinPepi statistical package (version 11.65). The statistical significance of the differences was assessed with a probability level of p ≤ 0.05.Results. The seroprevalence of the population of the Krasnoyarsk Territory during the 5-month period of seromonitoring had increased 3.3 times from 12.8% (95% CI 11.3–14.4) to 41.7% (95% CI 39.4–4.0) , while the grouping by age had not revealed any peculiarities throughout the study. The trend towards a decrease in the incidence was formed on the 6th week of 2021. The seroprevalence of convalescents after COVID-19 during the initial testing was 61.5% (95% CI 40,6–79.8), among those who were in contact with patients with COVID-19 or convalescents –23.8% (95% CI 13.9–36.2) . Among the volunteers, 347 seropositive persons were identified, 324 of which were observed asymptomatic course.Conclusion. The structure of the population humoral immunity to SARS-CoV-2 of he population of the Krasnoyarsk Territory has been investigated. It was found that an increase in seroprevalence to 41.7% (95% CI 39.4–4.0) was accompanied by a decrease in morbidity.

Relevance. At the end of 2019, the world was confronted with a novel coronavirus (SARS-CoV-2), In January 2020, WHO declared an epidemic related to SARS-CoV-2, a health emergency of international importance, and in March characterized the spread of the world. diseases like a pandemic.Purpose of the study. Conduct a comparative analysis of the seroprevalence of the population of the Sverdlovsk and Chelyabinsk regions – the largest administrative territorial entities of the Middle and Southern Urals – against the backdrop of the COVID-19 pandemic.Materials and methods. The work was carried out under the program of the first stage of assessing the seroprevalence of the population of the Russian Federation according to a unified methodology developed by Rospotrebnadzor of the Russian Federation with the participation of the Saint Petersburg Pasteur Institute. The selection of participants was carried out by the method of questioning and randomization. The presence of antibodies to the SARS-CoV-2 nucleocapsid was determined in blood serum by the enzyme immunoassay.Results. Comparative analysis of the results showed that the incidence rate of COVID-19 in the Chelyabinsk region was consistently lower, and the seroprevalence at the first stage of the study was statistically significantly higher (p Conclusions. A comparative study showed a statistically significant predominance of seroprevalence among the population of the Chelyabinsk region. It was found that an increase in seroprevalence at the population level was accompanied by a decrease in morbidity. Shown is a direct relationship between population density and the incidence rate. More than 90% of seropositive individuals in the compared areas showed asymptomatic course of coronavirus infection.

The aim of the study is to summarize the results of a study of seroprevalence of children to SARS-CoV-3, obtained during the implementation of the Rospotrebnadzor program to assess seroprevalence to the NC antigen SARS-CoV-2 of the population of 26 regions of the Russian Federation, conducted during the COVID-19 epidemic in 2020. Research methods: the study of seroprevalence in 26 model territories of the Russian Federation was carried out according to a unified methodology developed by Rospotrebnadzor with the participation of the St. Petersburg Pasteur Institute of Epidemiology and Microbiology. The method provided for the formation of a group of volunteers in a model federative entity, including children aged 1–17 years, in which the presence of antibodies to the SARS-CoV-2 nucleocapsid was determined in venous blood plasma by the enzyme-linked immunosorbent assay (ELISA). The examination of volunteers was carried out in 3 stages: June-August, September-October, December. Results: the study found that in most of the areas surveyed, children had a higher level of seroprevalence than adults. It is shown that high seroprevalence is accompanied by statistically significant decrease in morbidity (p0.05). The analysis of seroprevalence at all three stages revealed at least 3 variants of its dynamics: 1) continuous growth of seroprevalence in parallel with the development of the epidemic process; 2) an episodic change in the periods of increase and decrease in the level of seroprevalence; 3) a continuous decrease in seroprevalence at the level of the epidemic process. Comparative determination of seroconversion levels in three age groups – 1–6, 7–13 and 14–17 years – revealed no statistically significant differences between these age groups have been identified. Conclusion: children aged 1–17 years in most of the surveyed territories of the Russian Federation have a higher seroprevalence to SARS-CoV2 than adults. The increase in seroprevalence in children is accompanied by a decrease in the incidence of COVID-19.

The novel coronavirus (SARS-CoV-2) pandemic, dubbed COVID-19, has become one of the most serious challenges for human populations in the vast majority of countries worldwide. Rapid spreading and increased mortality related to it required new approaches to manage epidemic processes on a global scale. One of such approaches was based on analyzing SARS-CoV-2 seroprevalence associated with COVID-19. Our aim was to summarize the results on assessing seroprevalence to the SARS-CoV-2 nucleocapsid antigen (Nc) in residents from 26 regions of the Russian Federation, carried out during the first wave of the COVID-19 epidemic.Materials and methods. Seroprevalence distribution was examined in 26 model regions of the Russian Federation according to the unified method developed by the Rospotrebnadzor with the participation of the Federal State Institution Saint Petersburg Pasteur Research Institute of Epidemiology and Microbiology. Such approach implied formation of a group of volunteer subjects in model geographic region who were tested by ELISA for anti-Nc serum antibody level in peripheral blood. Analyzed primary data obtained in separate regions were either accepted for publication or released.Results. The current paper finalizes the data obtained in all 26 regions of the Russian Federation. The total SARS-CoV-2 seroprevalence was 19.5 (10.0–25.6)% with the maximum and minimum value found in the Kaliningrad Region and the Republic of Crimea, respectively (50.2% vs. 4.3%). A pattern of age-related seroprevalence distribution indicates insignificant predominance of seroprevalence among subjects of 1–17 years old: 22.1 (13.1–31.8)%. Among COVID-19 convalescents positive for SARS-CoV Nc antibodies it reached 60.0 (40.0–73.3)%. The number of contact persons comprised 6285 subjects or 8.5% of total volunteer cohort, with the level of seroprevalence reaching up to 25.3 (17.95–35.8)%. A direct correlation was revealed between levels of seroprevalence in convalescent and contact volunteers. In addition, the reproductive number for SARS-CoV was calculated comprising 5.8 (4.3–8.5) suggesting that one convalescent subject can infect at least 4 healthy individuals. A high level of asymptomatic forms of COVID-19 among seropositive subjects was confirmed empirically comprising up to 93.6 (87.1–94.9)%.Conclusion. A single cross-sectional study performed during 2020 June–August timeframe allowed to assess pattern of sex- and agerelated COVID-19 seroprevalence for general population in 26 Russian Federation regions. The data obtained may serve as a basis for the longitudinal cohort investigation with serial subject sampling. The timing and duration of study will be determined by dynamics of ongoing COVID-19 epidemic.

Introduction. The coronavirus disease (COVID-19) pandemic was announced by WHO in February 2020. In the Khabarovsk Krai, the first three cases of the disease were diagnosed on March 19, 2020, these cases were imported from Argentina (transit through Italy). The epidemic process of COVID-19 in the Khabarovsk Krai is characterized by a slow increase in the incidence. During the period of time when the SARS-CoV-2 seroprevalence study was conducted the incidence rates varied from 35.9 to 39.1 per 100 thousand population. Within the next 5 weeks the incidence continued to increase, the maximum level was 67.3 per 100 thousand population. A statistically significant decrease in the incidence is noted in the first decade of August. The study of the SARS-CoV-2 seroprevalence among residents of the region was carried out from June 9 to June 21, 2020 during the period of increasing intensity of the epidemic process of COVID-19 infection.Aim. To determine the level and structure of herd immunity to SARS-CoV-2 virus among the population of the Khabarovsk Krai during the period of intensive spread of COVID-19.Materials and methods. The study was conducted as a part of the first stage of a large-scale Rospotrebnadzor project to assess the herd immunity to SARS-CoV-2 virus among the population of the Russian Federation, taking into consideration the protocol recommended by WHO. The selection of volunteers for the study was carried out by the method of questionnaires and randomization by random sampling. The results of a survey of 2675 individuals were included into analysis. The number of volunteers in all age groups was similar.Results. The results of the study showed that the herd immunity to SARS-CoV-2 in the total population of the Khabarovsk Krai was 19.6%. The maximum level of herd immunity was observed in children 14–17 years old (34.4%), children 7–13 years old (24.8%), and people over 70 years (22.6%). The highest level of seropositivity, except for the children and the elderly, was found among educational workers (26.7%). The lowest level of seropositivity was found in the military (8.7%) and the unemployed (8.3%). There were no statistically significant differences in the level of seroprevalence between men and women.Conclusions. The results of the seroepidemiological study demonstrated that in the Khabarovsk Krai, the presence of the contacts with COVID-19 patients is associated with the 1.4-fold increase in the likelihood of the seroconversion. Antibodies were detected in 58.9% of the past COVID-19 cases. In individuals with the previous positive PCR test result, antibodies were detected in 50% of cases. A high rate of asymptomatic infection, up to 93.7%, was observed among seropositive volunteers.

The first reports about HIV (human immunodeficiency virus) were appeared to the 1980s. By 2017 more than 37 million people were living with HIV. Human papilloma virus (HPV) is universally spread, with some estimates showing that about 1% of the sexually active population having genital warts. Human papilloma virus (HPV)-induced infection frequently accompanies the clinical course of HIV and can manifest itself in a full spectrum of clinical-pathologic forms ranging from common warts to malignant neoplasia. Due to the widespread use of antiretroviral therapy, the number of patients with a combined infection (HIV+HPV) is steadily increasing. Here we review current clinical treatment options for HPV manifestations. High-dose antiretroviral therapy does not impede HPV treatment, and can even improve its efficacy in some cases. The topical administration of imiquimod, an immune response modifier, is an effective conservative treatment in HIV-infected patients with HPV. The immunomodulation therapy of imiquimod can serve as an effective alternative of aggressive chemical and mechanical procedures. Maximum efficacy with the lowest replaces rates may be expected from combined use of mechanical ablation methods with a subsequent follow up treatment with imiqui-mod. The best therapeutic result is expected in HIV-positive patients who are received high-dose antiretroviral treatment. The advantages of Vartocid, the modified Russian equivalent of the generic imiquimod.

By August 2020, more than 850000 cases of new coronavirus infection (COVID-19) caused by SARSCoV-2 were confirmed in the Russian Federation, with the Rostov Region as one of the ten most affected regions in Russia. The spread of the disease is largely determined by the state of population immunity in a certain area. Our research focuses on specific humoral immune response and estimates the level of herd immunity to SARS-CoV-2 virus among the population of the Rostov Region.Materials and methods. The study involved 3,048 people; the volunteers participating in the study were divided into seven age groups. The content of antibodies to SARS-CoV-2 was determined applying ELISA using a kit for the analysis of human serum or blood plasma for the presence of specific IgG to the nucleocapsid of the SARS-CoV-2 virus, manufactured by the State Scientific Center of Applied Microbiology and Biotechnology (Obolensk) in accordance with the instructions for use.Results and discussion. The assessment of seroprevalence to SARS-CoV-2 in the Rostov Region showed that the proportion of people positive for IgG to the new coronavirus was 16.5 %, the range of seropositive individuals in the general population was between 13.9 % and 19.1 % (p

The global community is experiencing one of the largest infectious disease outbreaks in the 21st century. In the Saratov Region, the first case of new coronavirus infection was confirmed on March 19, 2020.The maximum increase in cases was noted between May 15 and June 30, during that time the total number of infected people in the region increased from 1526 to 6444. Since July 2020, a stable incidence level of new coronavirus infection has been observed in the Saratov Region, without a steady decline.The aim of the study was to assess the status of population immunity to the SARS-CoV-2 virus among residents of Saratov and the Saratov Region under the COVID-19 epidemic.Materials and methods. In the period from June 23 to July 26, 2020, a serological study of blood samples from 3372 volunteers of different age groups was conducted. The content of antibodies to SARS-CoV-2 was determined by ELISA using a set of reagents “ELISA anti-SARS-CoV-2 IgG” produced by the State Scientific Center of Applied Microbiology and Biotechnology of the Rospotrebnadzor (Russia).Results and discussion. In general, the incidence of COVID-19 in the Saratov Region is taking place against the background of moderate seroprevalence to the SARS-CoV-2 virus, accompanied by a high incidence of non-apparent (asymptomatic) forms of the infectious process. The absence of clinical symptoms of the disease, in the context of the limited use of methods for determining the RNA of the SARS-CoV-2 virus in PCR (11 % of the region’s population) makes it difficult to assess the real spread of the virus in the population and to establish the timing of the formation of persistent herd immunity. A low rate of antibody response among individuals with a positive result of PCR analysis, as well as among volunteers who had an infection in May, June 2020, indicates a weak formation of the immune response, or the prevalence of individuals reacting mainly by activating the cellular link of the immune system in the population. The obtained results, although they need to be explained in a number of respects, can be applied to the organization of preventive measures, including vaccination, in the region.

In late 2019, there were reports of an outbreak of infection caused by a new strain of beta coronavirus SARSCoV-2, the WHO identified the disease as coronavirus disease 2019 (COVID-19). In Tatarstan, the first case of COVID-19 was diagnosed on March 16, 2020, it was an imported case from France. The period of increase in the incidence lasted during the 12th to the 19th week, when the highest rate was recorded, amounting to 16.7 per 100 thousand population. Subsequently, a statistically significant decrease in the incidence was noted. Seroprevalence study was conducted at week 27 (8th week of decline of morbidity).The purpose of the seroepidemiological study was to measure the level and to identify the structure of herd immunity against the SARS-CoV-2 virus among the population of the Republic of Tatarstan during the rapid spread of the COVID-19 outbreak.Materials and methods. The selection of volunteers for the study was carried out by the method of questionnaires and randomization by random sampling. The exclusion criterion was active COVID-19 infection at the time of the survey. 2,946 people were examined for the presence of specific antibodies to SARS-CoV-2. The age of the surveyed volunteers ranged from 1 year to 70 years and older.Results. The results of the study showed that in the Republic of Tatarstan during the period of COVID-19 incidence, there was a moderate seroprevalence to SARS-CoV-2, which amounted to 31.3%, against the background of a high frequency (94.5%) of asymptomatic infection in seropositive individuals who did not have a history of past COVID-19 disease, positive PCR result and ARVI symptoms on the day of the examination. The maximum indicators of herd immunity were established in children aged 7–13 years (42.0%), children 14–17 years old (40.3%), with a simultaneous decrease in seroprevalence in persons aged 70 and older (24.0%). In different regions of the Republic of Tatarstan, there was a wide variation in seropositivity results from the minimum in the Zainsky district (8.6%) to the maximum in the Arsky district (74.3%). In 21 out of 38 surveyed districts, the results were unrepresentative due to the small sample size. In COVID-19 convalescents, antibodies are produced in 83.3% of cases. In persons with a positive result of the PCR analysis carried out earlier, antibodies were detected in 100% of cases. Among the volunteers who had contact with patients with COVID-19, the proportion of seropositive is 37%Conclusion. The dynamics of seroprevalence among the population of the Republic of Tatarstan can be qualified as positive, the results obtained can be used to develop a forecast for the development of the epidemiological situation, as well as to plan measures for specific and non-specific prevention of COVID-19.

Introduction. The COVID-19 pandemic was announced by WHO in February 2020. In the Kaliningrad region, the first case (imported) was registered in early March 2020, the beginning of the epidemic increase fell on the 14th week. 2020, and the peak incidence was reached in the 22nd week of the year, after which there was a steady decrease in the number of cases. The study of population immunity was carried out at the 32nd week during the period of the lowest level of intensity of the epidemic process.Purpose of the study. Assessment of the assessment of the level of population immunity to the SARS-CoV-2 virus among the population of the Kaliningrad region during the period of the epidemic incidence of the population of COVID-19.Materials and methods. The study was carried out as part of the first stage of the Rospotrebnadzor program to assess population immunity to SARS-CoV-2 among the population of the Russian Federation. The selection of volunteers for the study was carried out by a questionnaire survey and subsequent randomization. The analysis includes the results of a survey of 2675 people. The number of volunteers in age groups ranged from 314 to 493 people. The results obtained were processed by the methods of variation statistics.Results. The results obtained showed that the average seroprevalence in the population was 50.2%, while the highest seroprevalence was found in the child age group 1-17 years (66.9%) and among persons aged 18-29 (57.0). No significant gender differences were found (men – 48,3 ± 1,6%, women – 51,1 ± 1,1%). The distribution of the proportion of seropositive people in the settlements of the region varied from 33,9% to 59.6%. The largest share of seroprevalence in the representative samples was found among people engaged in art / creativity (55,3%), the smallest – among educational workers (42,0%). Among COVID-19 convalescents, the level of humoral immunity reached 94,6%. Most of the seropositive volunteers (95,2%) did not have any symptoms of COVID-19, that is, they belonged to the category of asymptomatic carriers.Output. The results of a survey of a representative cohort of volunteers in the Kaliningrad region showed that they are characterized by a high level of population immunity, which makes it possible to expect a decrease in.

The first case of COVID-19 was registered in the Leningrad Region on March 13, 2020. The period of increasing intensity of the epidemic process lasted 8 weeks. One month after reaching the maximum incidence rate, a study was organized to determine seroprevalence to COVID-19 among the population of the Region.Objective of the study was to determine the level and structure of community immunity to SARS-CoV-2 virus in the population of the Leningrad Region in the period of intensive COVID-19 transmission.Materials and methods. The work was carried out within the framework of the Rospotrebnadzor project on assessment of community immunity to the SARS-CoV-2 virus in the population of the Russian Federation. The content of antibodies to SARS-CoV-2 was determined applying ELISA using a kit for the analysis of human serum or blood plasma for the presence of specific IgG to the nucleocapsid of the SARS-CoV-2 virus , manufactured by the State Scientific Center of Applied Microbiology and Biotechnology (Obolensk) in accordance with the instructions for use.Results and discussion. The study has showed that the herd immunity of the population of the Leningrad Region was 20.7 %. The maximum level has been established in children 1–6 years old (42.3 %) and people over 70 years old (29.0 %). The highest level of seropositivity, except for children and older people, was found among the unemployed (25.1 %). The lowest level of seroprevalence was detected in civil servants (12.8 %) and military personnel (16.7 %). It has been shown that the risk of infection increases by 1.5 times in case of contacts with COVID-19 patients. After exposure to COVID-19 virus, antibodies are produced in 82.1 % of the cases. In individuals with a positive PCR test result obtained earlier, antibodies are detected in 82.8 % of cases. The share of asymptomatic forms among seropositive residents of the Leningrad Region was 86.9 %. The results of assessing the herd immunity to SARS-CoV-2 in the population of the Leningrad Region indicate that during the period of intensive COVID-19 transmission, an average level of seroprevalence was formed. A significant proportion of asymptomatic forms of infection characterizes the high intensity of the latently developing epidemic process. The results obtained should be taken into account when organizing preventive measures, including vaccination, and predicting morbidity rates.

Objective of the seroepidemiological study was to determine the level and structure of herd immunity to SARS-CoV-2 among the population of the Irkutsk Region during the period of an increase in the incidence of COVID-19.Materials and methods. The content of antibodies to SARS-CoV-2 was determined by ELISA applying a reagent panel “ELISA anti-SARS-Cov-2 IgG” produced by the State Scientific Center of Applied Microbiology and Biotechnology (Obolensk).Results and discussion. The investigation has revealed that the herd immunity of the total population of Irkutsk Region amounted to 5.8 %. The greatest share of seropositive persons was among the children aged 14–17 (13.8 %) and 1–6 (11.8 %). It has been established that the risk of infection increases by 3.1 times in case of contact with COVID-19 patients. After exposure to COVID-19, antibodies were produced in 56.5 % of the cases. The share of asymptomatic forms among seropositive residents of the Irkutsk Region reached 81.2 %. Consequently, during the chosen period of increased COVID-19 incidence among the population of Irkutsk Region low level of seroprevalence was formed. A significant proportion of asymptomatic forms of infection characterize high intensity of the latently developing epidemic process. The results obtained can be used when organizing preventive measures, including vaccination, and for forecasting morbidity rates.

Due to the lack of COVID-19 specific preventive measures with a prophylactic and therapeutic (as part of complex therapy) purpose, various drugs were used as humanitarian aid from manufacturing companies to prevent influenza and SARS in St. Petersburg hospitals. The study of Russian Scientific Research Institute of Traumatology and Orthopedics named after R.R. Vreden patient treatment shows the possibility of using drugs containing a synthetic regulatory thymus peptide (L-glutamine-L-tryptophan-thymogen) as an active ingredient in a patient with an in-hospital coronavirus infection. This compound has a number of extra- and intracellular immunotropic effects of key importance in the pathogenesis of respiratory viral infections, including coronavirus etiology. The components have an indirect antiviral effect against acute respiratory viral infections, comprising COVID-19. This led to the use of drugs containing thymogen for the prevention and treatment of COVID-19. The use of immunotropic agents promoted the rapid involution in the patient of clinical, laboratory and instrumental (radiological) signs of the disease and its uncomplicated course both in the primary infection and the development of superinfection cases. The study has shown that the use for the prevention and treatment (as part of complex therapy) of drugs with immunomodulatory activity, as well as those capable of affecting various links in the pathogenesis of pulmonary lesions in coronavirus infection, seems to be highly relevant and justified.

The first case of COVID-19 was diagnosed in St. Petersburg on March 2, 2020; the period of increase in the incidence lasted for 10 weeks, the maximum rates were recorded in mid-May, and subsequently there was a statistically significant decrease in the incidence.Objective: to determine the level and structure of community immunity to SARS-CoV-2 among the population of St. Petersburg during the period of intensive spread of COVID-19.Materials and methods. Selection of volunteers for the study was carried out through interviewing and randomization. The exclusion criterion was active COVID-19 infection at the time of the survey. 2713 people aged 1 to 70 years and above were examined for the presence of specific antibodies to SARS-CoV-2. Antibodies were detected by enzyme immunoassay.Results and discussion. Studies have shown that in St. Petersburg, in the active phase of COVID-19 epidemic, there was a moderate seroprevalence to SARS-CoV-2, which amounted to 26 %, against the background of a high frequency (84.5 %) of asymptomatic infection in seropositive individuals who did not have a history of COVID-19 disease, positive PCR result and ARI symptoms on the day of examination. The maximum indicators of herd immunity were established in children 1–6 years old (31.1 %), 7–13 years old (37.7 %) and people over 70 years old (30.4 %). Differences in the level of seroprevalence in the age groups of 18–49 years are statistically significant. The highest level of seroprevalence was found among the unemployed (29.7 %), healthcare workers (27.1 %), education sector (26.4 %) and business sector personnel (25 %). In convalescents, COVID-19 antibodies are produced in 75 % of cases. In individuals with positive result of PCR analysis carried out earlier, antibodies are detected in 70 % of the cases. The results of the study of herd immunity to SARS-CoV-2 are essential to forecast the development of the epidemiological situation, as well as to plan measures for specific and non-specific prevention of COVID-19.

Here we review means of immunomodulatory therapy for coronavirus infection caused by SARS-CoV-2 (COVID-19). It has been appreciated that highly limited arsenal of relatively effective means and methods of prevention and treatment of the COVID-19 pandemic is available. The goal of our study was to analyze some therapeutic approaches based on available publications for COVID-19 treatment viewed from acting via innate immunity system. Convalescent plasma serotherapy represents one of the means with verified therapeutic efficacy that was accompanied with decreased viral load and relief of the disease symptoms. The drawback of serotherapy results from limited number of potential plasma donors and profound variety in amount of SARS-CoV-2-specific antibodies found in donor plasma. Another approach to COVID-19 therapy is based on using monoclonal antibodies engineered to target specific virus antigenic determinants, most often surface spike antigen. Antibodies blocking such antigen are able to prevent virus entrance into target cells and development of overt infection. On the other hand, there are monoclonal antibodies abrogating production or binding of excessive amounts of pro-inflammatory cytokines, such as IL-6, TNFα, etc., some of which (tocilizumab) have been already tested in COVID-19 therapy, whereas the remaining preparations are being currently investigated and tested. A certain breakthrough in COVID-19 therapy was provided by the well-known drugs chloroquine and dihydrochloroquine, which have proven to be effective as antiviral, anti-inflammatory and immunomodulatory means. Finally, a new multicomponent immunomodulatory preparation Cytovir-3 has been proposed already passed clinical trials and recommended for use in prevention and treatment of influenza and SARS and might have found its own niche in preventing COVID-19, as SARS-CoV-2 also belongs to the group of acute respiratory viruses. Thus, the arsenal of means for COVID-19 prevention and treatment contains the drugs for immunomodulatory therapy and prevention of immune-related disorders developing in response to invasion pathogenic viruses and lowering a risk of possible damage. Hence, correct and scientifically justified use of such remedies will increase overall effectiveness of fight against the coronavirus pandemic.

Coronaviruses (CoVs) comprise a polymorphic group of respiratory viruses causing acute inflammatory diseases in domestic and agricultural animals (chicken, pig, buffalo, cat, dog). Until recently, this infection in humans was mainly observed during the autumn-winter period and characterized by a mild, often asymptomatic, course. The situation changed dramatically in 2003, when SARS outbreak caused by pathogenic CoV (SARS-CoV) was recorded in China. A decade later, a new CoV outbreak occurred in the form of the Middle East respiratory syndrome (MERS-CoV), whereas in December 2019, SARS-CoV-2 (COVID-19) cases were recorded, which transformed within the first months of 2020 into the pandemic. In all three cases, CoV disease led to severe bronchopulmonary lesions, varying from dry, debilitating cough to acute respiratory distress syndrome (ARDS). At the same time, multiple changes in innate immunity were noted most often manifested as a pronounced inflammatory reaction in the lower respiratory tract, featured by damaged type II pneumocytes, apoptosis, hyalinization of alveolar membranes, focal or generalized pulmonary edema. Destructive processes in the respiratory tract were accompanied by migration of monocytes/macrophages and granulocyte neutrophils to the inflammatory focus. Such events were accompanied by production of pro-inflammatory cytokines, which magnitude could ascend up to a cytokine storm. SARS-CoV is characterized by symptoms of secondary immunosuppression, manifested by the late onset of interferon production and activation of NLRP3 inflammasomes – the key inflammatory factor. The reason for such reaction may be accounted for by CoV arsenal containing extensive set of structural and non-structural proteins exerting pro-inflammatory and immunosuppressive properties. Delayed IFN production allowed CoV to replicate actively and freely, and when type I IFN synthesis was eventually triggered, its activity was detrimental and accompanied by an aggravated infection course. Thus, SARS can surely be referred to immune-dependent infections with a marked immunopathological component. The purpose of this review was to describe some mechanisms underlying formation of innate immune response to infection caused by pathogenic coronaviruses SARS-CoV, MERS-CoV and SARS-CoV-2 (COVID-19).

Aim: To compare the safety and prophylactic efficacy of Cytovir-3 and Arbidol in an open-label randomized clinical trial in children at seasonal risk of infectious respiratory disease.Methods: This study was performed in the period preceding a seasonal outbreak of acute respiratory viral infections (ARVI) and influenza. The study enrolled apparently healthy children aged 6 to 18 years without contra-indications to either Cytovir-3 or Arbidol. Cytovir-3 was given as 1 capsule per day, each day in a fasted state for 12 days. Arbidol was taken as a 100 mg capsule twice a week for three weeks. Following dosing, subjects were followed-up for a further three weeks. Overall health and presence of symptoms of either ARVI or influenza were monitored daily in all subjects. The level of sIgA in saliva was baselined before treatment and measured at the end of the follow-up period.Results: Most subjects did not exhibit any change in overall health status during the dosing and follow-up periods. The first two cases of illness in subjects receiving Cytovir-3 were diagnosed at the end of the third week after completion of dosing. In those subjects receiving Arbidol the first cases of illness were reported at the end of the second week following the end of prophylactic dosing. All patients displayed a significant increase in sIgA level at the end of the dosing period, but this was more pronounced in the Cytovir-3 group. Conclusion: The results of this comparative randomized clinical trial confirmed the safety and tolerability of both medications, and that the prophylactic efficacy of Cytovir-3 is equal to that of Arbidol.

Imiquimod is an imidazole derivative acting as an immunomodulator on the level of innate and adaptive immune system. Our objective was to evaluate the antiviral activity of generically reproduced imiquimod administered subcutaneously in mice and intravaginally in guinea pigs against herpes simplex virus (HSV), as well as to study the dynamics of serum interferon (IFN) synthesis under different dosing regimens.When administered subcutaneously at doses of 0.5, 1.0 and 10 mg/kg imiquimod increased IFN production in mice in a dose-dependent manner with maximum serum IFN concentrations occurring 4 hours after dosing. Imiquimod protected mice from intraperitoneal HSV infection at doses of 3.2 and 32 LD50.The utmost protection (100% survival) was observed when imiquimod was administered at a dose of 100 mg/kg daily for 5 days before infection. Topical application of imiquimod 5% cream exhibited significantly more rapid and complete virus elimination in guinea pigs intravaginally infected with HSV type 2 compared to control group.Imiquimod produced as a generic possesses the same immunomodulatory and antiviral properties as the originally synthesized substance.Производное имидазола - имихимод - относится к иммуномодуляторам, действующим на врожденную и адаптивную системы иммунитета. Целью исследований было изучение динамики синтеза сывороточного интерферона (ИФН) при разных режимах дозирования и оценка противовирусной активности воспроизведенного в России препарата имихимода в отношении вируса простого герпеса (ВПГ) при его подкожном применении мышам и интравагинальном - морским свинкам. Результаты. При подкожном введении имихимода мышам в дозах 0,5; 1 и 10 мг/кг наблюдали дозозависимое увеличение выработки ИФН, пик концентрации которых достигался через 4 ч после введения. Применение имихимода защищало лабораторных животных (мышей) от внутрибрюшинного заражения ВПГ в дозах 3,2 и 32 ЛД50. При этом максимальный защитный эффект (100% выживаемость) достигался при введении имихимода в дозе 100 мкг/кг ежедневно в течение 5 дней до заражения. Топическое применение имихимода в виде 5% крема по сравнению с контрольной группой сопровождалось достоверно более быстрой и полной элиминацией вируса при интравагинальном заражении морских свинок ВПГ 2-го типа. Заключение. Воспроизведенный аналог имихимода обладает иммуномодулирующими и противовирусными свойствами, выявленными у первоначально синтезированного химического соединения.

Precise measurement of straw axial coordinate (along the anode wire) with accuracy compatible with straw radial coordinate determination by drift time measurement and increase of straw detector rate capability by using straw cathode readout instead of anode readout are presented., Comment: 16 pages, 10 figures

The article presents the results of clinical studies on the comparative effectiveness of different forms of the drug Cytovir-3 (syrup and powder for solution for oral administration) and Immunal l in the treatment of acute respiratory viral infections in children. It was found in a comparative randomized parallel-group study of 90 children aged two through six years that the drug Cytovir-3 (syrup and powder) became active faster than the comparison drug Immunal, providing normalization of body temperature, reduction of some manifestations of the general intoxication and respiratory syndrome, as well as elevated levels of serum immunoglobulin A. All drugs in the study had an equally normalizing effect on the content of peripheral blood leukocytes and erythrocyte sedimentation rates. The compared products were characterized by good tolerability, lack of side effects and high preventive efficacy against respiratory disease complications. Cytovir-3 drugs (syrup and powder for oral solution) and Immunal had similar ratios of clinical and laboratory safety, efficacy and tolerability. Both products can be used for the treatment of respiratory diseases in children aged two through six years.В статье представлены материалы клинического исследования, посвященного изучению сравнительной эффективности различных лекарственных форм препаратов Цитовир-3 (сироп и порошок для приготовления раствора для приема внутрь) и Иммунал при лечении острых респираторных вирусных инфекций у детей. В ходе сравнительного рандомизированного исследования в параллельных группах из 90 детей в возрасте от 2 до 6 лет было установлено, что препарат Цитовир-3 (сироп и порошок) способствовал более быстрому, чем препарат сравнения Иммунал, купированию температурной реакции, редукции некоторых проявлений общей интоксикации и респираторного синдрома, а также повышению содержания сывороточного иммуноглобулина А. Все исследуемые препараты в равной степени оказывали нормализующее влияние на содержание лейкоцитов периферической крови и скорость оседания эритроцитов. Препараты сравнения характеризовались хорошей переносимостью, отсутствием побочных реакций и высокой профилактической эффективностью в отношении осложнений респираторной патологии. По соотношению клинико-лабораторной эффективности, безопасности и переносимости Цитовир-3 и Иммунал сопоставимы и могут применяться для лечения респираторной патологии у детей от 2 до 6 лет.

Detector rate capability is one of the main parameters for designing a new detector for high energy physics due to the permanent rise of the beam luminosity of modern accelerators. One of the widely used detectors for particle track reconstruction is a straw-detector based on drift tubes. The rate capability of such detectors is limited by the parameters of readout electronics. The traditional method of increasing detector rate capability consists in increasing their granularity (the number of “elementary” detectors = readout channels) by reducing the straw diameter and/or by dividing the straw anode wire into two parts (for decreasing the rate per readout channel). A new method of designing straw detectors with a high rate capability is presented and tested. The method is based on dividing the straw cathode into parts and the independent readout of each part.

Materials and methods. The composition of glyzyrrhizic acid and glutamyl-tryptophane in the form of cream was studied using white rats. ACD was induced by application of the ethanol-acetone solution of 2,4-dinitrochlorobenzene (DNCB) during 4 days. The investigational drug was applied to the ACD lesions once a day during 14 consecutive days. The severity of ACD was assessed by the condition of the lesion focus, morphological composition of blood and apoptosis rate in the lesion. Results. It was shown that 4 days application of DNCB causes typical skin lesion manifesting in local papulovesicular eruptions, excoriations, and forming crust on the surface of the lesion. Application of the topical drug Tiladerm in the form of cream on the lesion induces significant acceleration of the lesion focus rehabilitation as early as on the end of 14 day of treatment. The activation of the markers of apoptosis (Ki-67, to a less extend p-53, caspase-3, Bcl-2) in the ACD lesion was shown. During treatment with Tiladerm, Ki-67 expression was reduced while expressions of p-53 and caspase-3 were enhanced. Conclusion. Thus, Tiladerm showed prominent positive effect on experimental ACD in rats.

The influence of components on the properties of anaerobic gasket seals is studied using the mathematical design of experiment. The efficiency of anaerobic gasket seals is determined. The equipment for applying gasket seals during in-line assembly is developed.

Background. To study the clinical effectiveness of topical immune modulator cream thymogen 0,05% and its influence on some immunological parameters in the skin and blood of atopic dermatitis (AD) patients. Materials and methods. 40 people were included in the study, who were divided into main (AD patients, n=20) and a control group (healthy donors, n=20). All AD patients received topical treatment with cream thymogen 0,05% during 14 days. Patients applied cream to affected skin 2 times daily. Clinical efficacy of the treatment was assessed by changes of following parameters: investigated global assessment (IGA), subjective evaluation of the itch intensity and skin dryness . Samples of skin biopsies and peripheral blood of AD patients and healthy donors were tested for gene expression of cytokines by polymerase chain reaction in real time. Results. Topical treatment with cream thymogen 0,05% during 14 days in all AD patients showed positive clinical effect: reduction of dryness and itch. Immunological analysis revealed a significant increasing of cytokine IL-7 gene expression and decreasing of cytokines IL-8, IL-5 genes expression (p

The fundamental design of BREST-OD-300 and BREST-1200 reactors is presented. It is shown that it is necessary to develop nuclear energy complexes based on the BREST nuclear system. The stages, the status of scientific research and development work over the entire nuclear power complex, and the results of an expert analysis of the BREST-OD-300 design are presented.

A high-voltage transistor voltage divider for photomultiplier tubes consists of a high-resistance linear resistive divider specifying potential distributions between dynodes and emitter followers maintaining this distribution. The divider features a low dissipation power and stable gain of the photomultiplier tube, when the average anode current varies in the entire measurement range.

The properties of photomultiplier tubes operating in the gating mode as components of scintillation detectors were investigated in high-power pulsed electromagnetic and nuclear radiation fields. Photomultiplier tubes with Venetian blind and linear focused dynode systems were considered. The diagrams of the gating circuits for the photomultipliers based on high-voltage dividers of the active and resistor types are presented. The results of our investigations are significant for a large number of experiments involving discrimination in time between the preceding background radiation and the useful signal.

Based on solving a boundary problem for a ring gas laser with a reversal mirror, conditions necessary for the realization of the unidirectional generation regime are established. Under these conditions, anomalies arise in the frequency dependence of the laser energy. They are manifested through the occurrence of relatively high peaks compared to the conventional Lamb dip. The unidirectional generation regime has been realized for an argon laser at a wavelength of 4880 A.

A detector with a profile-based cathode and a two-coordinate cathode readout system has been experimentally investigated. Cathode pads located in each profile along the anode wire are diagonally interconnected, thus forming strips that cross the detector at some angle with respect to the anode wire. Owing to the availability of the two cathode coordinates and the coordinate associated with the anode wire, it is possible to solve the problem of identifying high-multiplicity events in a single detector.

Under discussion are such major aspects of the nuclear energy sector as cost effectiveness, nuclear and environmental safety of reactors and nuclear fuel cycle facilities, sustained fuel supply, and proven feasibility of a proliferation-resistant technology. These requirements can be met, for instance, by a two-circuit nuclear facility with an inherently safe fast reactor of the BREST type which is expected to produce electricity at a cost not higher than that at modern LWRs. Fuel supply to such facilities and to a relatively small number of thermal reactors with BR

In the Bovanenkovo field, which is located in the permafrost zone, production from gas wells encounters the following problems: The high ice content of rock in the upper part of the section and the low rock temperatures (below -5~ are responsible for periodic collapse of the rock in the space near the well bore, loss of stability of cementing, misalignment of fittings, increased probability of flow of gas between strings, and so on, as a result of the heating effect of the gas flow on this space; other adverse effects include the collapse of casing strings when the fluid remaining outside the casing after drilling and cementing operations refreezes nonuniformly during a period of well shutdown, in the interval before the start of production, or during a period of conservation. The most effective means for preventing these problems is the use, in the operation or conservation of wells, of thermally insulated casing or tubing with a thermal resistance high enough to ensure extended operation of the well while maintaining a subfreezing temperature outside the casing; another possibility is the use of higher-strength casing with a critical crushing pressure higher than the maximum pressure created by the freezing liquid in one interval or another of the frozen ground with a known natural subfreezing temperature. In selecting a well program for conditions of the Bovanenkovo field (Aptian horizons), the following features were taken into account. No thermal insulation or "passive" thermal protection in permafrost is capable of eliminating the gradual

The coordinate detectors based on straw tubes provide a high accuracy of the radial coordinate measurement using the drift time and a small amount of matter in the way of the measured particles. However, the measurement of the coordinate along the wire constitutes a problem. This paper proposes a method for measuring the hit coordinate along the wire with an accuracy better than 1 mm in a straw tube detector using the signals from the cathodes of the detector., Comment: 5 pages, 5 figures, submitted to Instrum. Exper. Tech.(Pribory i Tekhnika Eksperimenta)

One of the principal means of disclosing internal latent production capacities consists of a systematic definition of the production programme for each establishment and the industry as a whole by computer techniques. The writers carried out research relating to the optimization of the production programme for all establishments producing viscose rayon textile yarn and staple fibre. The task entailed a large volume of preliminary work.

The space-time properties of the correlator of the light intensities scattered from resonant atoms are studied. It is shown that in measuring such a correlator by the method of optical shifts, an appreciable contribution appears from the anomalous correlator of the scattered field amplitudes. It is simple to observe this correlator in the field of a standing wave by measuring the correlation of oppositely scattered rays. The spectral and polarization properties of such a correlator are studied. Its investigation is of interest for high-resolution spectroscopy because it allows information to be obtained on the natural width of a line in conditions of strong Doppler broadening. It is important to stress that this is possible in a linear approximation with respect to the strength of the external field in contrast to the methods of laser spectroscopy based on nonlinear effects.

The anomalous correlator of the complex amplitudes of a scattered field is calculated. It differs from zero in a running wave for forward scattering, and in a standing wave for oppositely directed scattered rays. The anomalous correlator can be used in measuring the width of atomic resonances on the background of strong Doppler broadening in a linear approximation according to the intensity of the external field.

The results are given of theoretical and experimental investigations of stimulated emission from a modelocked negative-feedback solid-state (ruby) laser. Under certain conditions, governed by the delay time in the feedback circuit, the laser suffers from high-frequency instabilities in the form of sehvlocked intermode beats. These instabilities increase significantly the stringency of the requirements which have to be satisfied if negative feedback is to be used for amplitude stabilization.

The Leningrad Branch of the All-Union Scientific Research Institute for Man-Made fibres has prepared a summary of the main scientific and design developments utilized by the industry by the end of 1968 or the beginning of 1969. This summary permits an assessment of the activities of the branch not only from the technical point of view but also in economic terms, together with a comparison of the actual with the planned results.

The results are given of an experimental investigation of the amplitude and spectral characteristics of the emission of a ruby laser excited by external light pulses. It is shown that such excitation can stabilize the frequency and amplitude of the output radiation of the ruby laser. The dependences of the degree of stabilization of the frequency and amplitude of the output radiation on the difference between the frequencies of the laser output and the external signal are reported.