ABSTRACT
Relevance. The incidence of the novel coronavirus infection is on the rise worldwide. To effectively combat COVID-19, both vaccination and control of the circulation of SARS-CoV-2 strains among the population and, especially, foreign citizens arriving in Russia from around the world are necessary. Aim. To determine the frequency of detection of SARS-CoV-2 RNA in foreign medical students vaccinated against COVID-19 with various vaccine preparations. Materials and methods. Foreign students (510 people) of a medical university aged 18-25 years, vaccinated against COVID-19, who arrived in Russia during June-August 2021, were examined. The determination of SARS-CoV-2 RNA was carried out weekly from December 2021 to January 2022 by taking smears from the oropharynx and examining them using a test-PCR systems manufactured by the Federal State Budgetary Institution of the Central Research Institute of Epidemiology of Rospotrebnadzor «AmplisensCov-Bat-FL» (registration certificate No. RZN 2014/1987 dated 07.04.2020). Results. SARS-CoV-2 RNA was detected in 41 (8.0% [95% CI 5.6÷10.4]) of 510 international students surveyed. Among those vaccinated with vector vaccines based on human adenovirus (Sputnik V, Sputnik Light, Ad26. COV2.S (Johnson&Johnson)) SARS-CoV-2 RNA was detected in 27 (7.6% [95% CI 4.8÷10.4]) a person, mainly after 4–6 months. after vaccination;vaccines based on modified mRNA (BNT162b2 (Pfizer/BioNTech), mRNA1273 (Moderna)) – 5.7% [95% CI 1.1÷10.3] people within six months after vaccination. The infectious process was asymptomatic in 39 people, in two (vaccinated with the BNT162b2 vaccine (Pfizer / BioNTech) and Sputnik Light) it had clinical manifestations of severe and moderate severity. Conclusion. Among foreign students vaccinated against COVID-19, in addition to two cases, asymptomatic carriers of SARS-CoV-2 have been identified, which may be a potential source of infection. This indicates the need for vaccination and timely revaccination of foreign and Russian students, as well as compliance with the anti-epidemic regime. © 2023, Numikom. All rights reserved.
ABSTRACT
Introduction. The pandemic caused by the SARS-CoV-2 virus is an important medical and social problem. It remains unclear the stability of the developed humoral immunity against the SARS-CoV-2 virus, the average duration of preservation of the titer of specific antibodies. The need to identify humoral mechanisms of immune defense in patients with COVID-19 determined the purpose of this study. The aim of the study – to evaluate the dynamics of changes in the content of specific IgG antibodies against various antigens of the SARS-CoV-2 virus and B-lymphocyte subpopulations throughout the year in people who have had COVID-19. Material and methods. The study included 90 patients who had undergone COVID-19 in various forms, subsequently divided into 2 groups: persons with asymptomatic and mild course (57 patients) and with moderate or severe course of the disease (33 patients). The dynamics of the concentration of specific antibodies to the SARS-CoV-2 virus was evaluated by enzyme immunoassay every 3 months for a year. The content of the total pool B-lymphocytes (naive B-lymphocytes, memory B-cells, regulatory B-lymphocytes) and various subpopulations was evaluated by flow cytofluorimetry. Results. When assessing the dynamics of IgG to the S-protein of the SARS-CoV-2 virus, their preservation was noted by the 12th month after recovery. In patients with severe and moderate COVID-19 forms, these indicators are significantly higher. More severe forms of COVID-19 are accompanied by significantly higher content level of memory B cells throughout the observation period. Conclusion. Moderate and severe forms of COVID-19 induce more persistent postinfectious humoral immunity, provided by an increase in memory B cells in comparison with lighter forms.
ABSTRACT
The problem of cardiovascular comorbidity becomes particularly relevant in the context of a pandemic, since it is known that cardiovascular diseases (especially arterial hypertension - AH and coronary heart disease - CHD) significantly increase the frequency of hospitalizations and fatal outcomes in patients with COVID-19. From these positions, it is fundamentally important to identify a group of individuals with a high prognostic probability of developing combined cardiovascular pathology in the cohort of patients with hypertension. There is a hypothesis about the genetic relationship between different diseases, which helps to identify their common genetic variants, which in turn makes it possible to determine new loci of susceptibility for each of the comorbid conditions. Recent data indicate the feasibility of developing this problem from the standpoint of genetic polymorphism. Material and methods: The work is based on the results of a comprehensive examination of 100 patients with AH. A molecular genetic study to determine the main variants of gene polymorphism was performed on a DT 96 amplifier manufactured by DNA Technology (Russia). The method for determining the variants of gene polymorphism was a polymerase chain reaction with real-time detection of the results. Results: All patients included in the study were divided into 2 groups: patients with AH without CHD - 62% (62 people) and patients with AH with CHD - 38% (38 people). The relationships of polymorphism of 9 main variants of genes involved in the pathogenesis of isolated AH and in combination with CHD were studied. When analyzing the frequency of the studied genes in patients with hypertension with and without CHD, statistically significant differences were obtained for the NOS3 T-786C polymorphic gene, which was significantly more common in comorbid patients. Patients with a combination of AH and CHD are characterized by the presence of the CC genotype and the C allele of the VOS3 gene (p=0.040 and p=0.035), while the TT genotype of the T-786C polymorphic marker of the NOS3 gene is characteristic of patients with isolated AH. It should be noted that the carrier of the “mutant” allele C of the T-786C polymorphism of the NO3S gene, according to our calculated statistical data, increases the risk of CHD in patients with hypertension by 5 times (OR=5.242, p=0.035). Conclusion: The study of the genetic aspects of comorbidity is theoretically important for understanding the mechanisms of its formation. From a practical point of view, it is valuable to use modern genetic approaches for early detection of a prognostically unfavorable category of AH patients with a high risk of comorbid pathology developing.
ABSTRACT
Relevance. Currently, the incidence of COVID-19 is growing in many countries of the world, including Russia. There are suggestions about a likely protective role against the new coronavirus infection of widely used traditional vaccines against respiratory infections (influenza, tuberculosis, pneumococcal infection). Those vaccinated with these vaccines are less likely to report deaths and severe forms of COVID-19 diseases in vulnerable populations. The aim is to determine the frequency of detection of positive markers of a new coronavirus infection in individuals with different vaccination histories. Materials and methods. We examined 313 employees of an educational institution with various vaccination histories at the age of 20–54 years from May to September 2020. The determination of SARS-CoV-2 RNA and specific IgM and IgG antibodies to the virus nucleocapsid was carried out. Results. Positive markers for SARS-CoV-2 (PCR and / or ELISA) were found in 51 (16.3%) people. All examined patients had no signs of acute respiratory viral infections. Among people with positive markers of coronavirus infection (PCR and / or ELISA), the number of people vaccinated against diphtheria, tetanus, measles and hepatitis B (HBV) was 13.7–17.6% of those examined. Among those with negative PCR results, the number of people vaccinated against these infections was higher (p ≤ 0.05) and amounted to 51.0– 56.6%. Similar results were found in the determination of specific IgM and IgG. Conclusion. Positive markers of a new coronavirus infection were found much less frequently in persons who had a history of vaccination with ADS-M-toxoid, measles and hepatitis B vaccines. © 2021, Numikom. All rights reserved.