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Monitoring of the proportion of immune individuals and the effectiveness of vaccination in a population involves evaluation of several important parameters, including the level of virus-neutralising antibodies. In order to combat the COVID-19 pandemic, it is essential to develop approaches to detecting SARS-CoV-2 neutralising antibodies by safe, simple and rapid methods that do not require live viruses. To develop a test system for enzyme-linked immunosorbent assay (ELISA) that detects potential neutralising antibodies, it is necessary to obtain a highly purified recombinant receptor-binding domain (RBD) of the spike (S) protein with high avidity for specific antibodies. The aim of the study was to obtain and characterise a SARSCoV-2 S-protein RBD homodimer and a recombinant RBD-expressing cell line, as well as to create an ELISA system for detecting potential neutralising antibodies. Material(s) and Method(s): the genetic construct was designed in silico. To generate a stable producer cell line, the authors transfected CHO-S cells, subjected them to antibiotic pressure, and selected the optimal clone. To isolate monomeric and homodimeric RBD forms, the authors purified the recombinant RBD by chromatographic methods. Further, they analysed the activity of the RBD forms by Western blotting, bio-layer interferometry, and indirect ELISA. The analysis involved monoclonal antibodies GamXRH19, GamP2C5, and h6g3, as well as serum samples from volunteers vaccinated with Gam-COVID-Vac (Sputnik V) and unvaccinated ones. Result(s): the authors produced the CHO-S cell line for stable expression of the recombinant SARS-CoV-2 S-protein RBD. The study demonstrated the recombinant RBD's ability to homodimerise after fed-batch cultivation of the cell line for more than 7 days due to the presence of unpaired cysteines. The purified recombinant RBD yield from culture broth was 30-50 mg/L. Monomeric and homodimeric RBD forms were separated using gel-filtration chromatography and characterised by their ability to interact with specific monoclonal antibodies, as well as with serum samples from vaccinated volunteers. The homodimeric recombinant RBD showed increased avidity for both monoclonal and immune sera antibodies. Conclusion(s): the homodimeric recombinant RBD may be more preferable for the analysis of levels of antibodies to the receptor-binding domain of the SARS-CoV-2 S protein.Copyright © 2023 Authors. All rights reserved.
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Aim of the study was to evaluate the impact of anti-epidemic measures (CAM) complex on the dynamics of the epidemic process of COVID-19 in a controlled cohort of patients. Material and methods. Patients from 30 social long-term care institutions of the city were included in the study, including neuropsychiatric boarding schools, boarding houses for labor veterans, gerontological centers, and houses for stage veterans. A total of 8303 patients participated in the study, of which 4237 were men (mean age 53.6 years) and 4066 were women (mean age 62.0 years). Vaccination was carried out with Gam-Covid-Vac. Results and discussion. For the entire observation period from March 2020 to August 2021, 1619, cases of COVID-19 or 19.5% of the total number of patients were registered among patients. At the initial epidemic stage (spring-summer 2020), the incidence of COVID-19 among patients was explosive. At the same time, in the autumn-winter period of 2020, an increase in the incidence of COVID-19 was also observed. However, much less pronounced than in April 2020. Despite the progress, it was decided to strengthen the sanitary and anti-epidemic regime in institutions with the introduction of additional preventive measures. One of the most effective long-term algorithms for reducing the infectious disease incidence was vaccination. In this regard, the Moscow Department of Healthcare suggested the need for voluntary vaccination of 100% of patients in all institutions at the beginning of 2021. In the spring of 2021, the number of cases began to increase in the city. The increase in the incidence of COVID-19 was insignificant among the patients of institutions: the maximum number of cases detected in one month during this period was 13 people (in April), or 60.5 times less than in April 2020, and 2.5 times less than in October 2020. The incidence of COVID-19 has become sporadic rather than epidemic. Conclusion. The introduction of CAM in long-term care social institutions in the early stages of the epidemic contributed to a decrease in the incidence of COVID 19. 100% vaccination of patients in combination with other prevention measures reduced the incidence of COVID-19 by more than 28 times. At the same time, it was found that there is a trend of increasing incidence depending on the increase in the level of independent activity of patients.Copyright © 2023 The authors.
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Currently, as the SARS-CoV-2 pandemic evolves, there has been increasingly more attention paid to building natural and vaccine-induced immunity against SARS-CoV-2 and related disease known as COVID-19. Widespread pre-ventive vaccination plays an important role in effectively protecting people from viral infections and can reduce national economic costs. Purpose - to study peripheral blood cell subset composition and magnitude of humoral response in vac-cinated Gam-COVID-Vac subjects. The prospective study included 352 patients, of which 194 (119 women and 75 men) underwent an immunogram study and assessed level of anti-SARS-CoV-2 antibodies. In patients, the study of the lym-phocyte subset composition and estimation of anti-SARS-CoV-2 antibodies was carried out at two time points - prior to vaccination and 90 days after inoculated component 1 of the Gam-COVID-Vac vaccine. In general, vaccination was well tolerated by patients, with no serious adverse events after immunization. The reaction to the vaccine (fever, ma-laise, headache, local reactions) was short-term (1-2 days) and more often noted after inoculated vaccine component 2. Comparatively analyzed immunogram parameters in females before and after vaccination revealed increased relative level of T-lymphocytes (CD3+), T-helper cell subset (CD3+CD4+), increased absolute and relative level of activated CD3+CD25+ T-lymphocytes, but decreased absolute and relative level of natural killer (CD3-CD56+CD16+) and natural killer T-cell (CD3+CD56+CD16+) cell subsets as well as decreased CD147 receptor expression on T-lymphocytes. Similar patterns were also found while examining the immunogram in males exepting increased level of lymphocytes and lowered CD147 expression on both T-and B-lymphocytes. No changes in the parameters of the immune T-cell arm was found. The high efficacy of the vaccine was confirmed by development of SARS-CoV-2-specific class G antiviral antibodies in 97.5% and 92.3% of vaccinated females and males, respectively. The data obtained evidence that: 1) vaccination induces a specific humoral immune response determined three months post-vaccination, and 2) it caused no serious disturbances in the im-mune system functioning, which could be reflected in the peripheral blood lymphocyte subset composition. Thus, the data presented allow to conclude that Gam-COVID-Vac is effective vaccine against SARS-CoV-2 infection.
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Background: As a result of the COVID-19 pandemic, many vaccines were developed to counter the disease, including the vector-based Sputnik V vaccine. This study aims to identify the side effects of the Sputnik V COVID-19 vaccine in a medical center and compare the results with the previous reports. Methods: A questionnaire-based study was performed after the injection of the first and second doses of the vaccine to assess the side effects experienced by the participants. It was performed by reviewing similar previous studies. Results: Injection site pain, muscle pain, fever, fatigue, chills, and headache were the most common side effects of the vaccine. The incidence of major side effects decreased with age and was lower in men. In our study and others, the incidence of side effects was decreased in the second dose. In some studies, participants with a previous history of Severe Acute Respiratory Syndrome Coronavirus 2 (SARSCOV-2) infection developed more side effects, especially injection site pain, muscle pain, and fatigue. Conclusion: Most studies agree with our reported results. Serious side effects of this vaccine are rare and may be considered tolerable in adults.
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The clinical case describes the difficulties of differential diagnosis of polyneuropathy that developed, after Gam-Covid-Vac vaccination on the background, of combined, infectious pathology (HIV infection, tick-borne borreliosis, COVID-19) in a young woman. It is shown that various infectious and noninfectious diseases with similar clinical symptoms (peripheral nervous system, affliction.) occurring simultaneously in one patient can significantly affect each other's course and. complicate the establishment of the true cause of polyneuropathy. It should, be noted, that in this example, the establishment of a final diagnosis was carried out collectively, by consensus, and. was based, on the effectiveness of etiotropic (antibacterial) treatment, which in fact was an exjuvantibus therapy option, which made it possible to establish the most probable etiology of polyneuropathy -tick-borne borreliosis. In turn, HIV infection and. possibly vaccination, according to the authors, could, cause immunosuppression, which, affected, the degree of dissemination, of Borrelia burgdorferi. It is also likely that the insufficient immune response in combination. with the cascade plasma filtration session affected the initial dubious results of the serological tests, which further complicated. the diagnosis.Copyright © 2022 Authors. All rights reserved.
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OBJECTIVES: The aim is to study impact of vaccination against the novel coronavirus disease (COVID-19) with Sputnik V on mortality during the period of predominance of the delta variant of SARS-CoV-2. METHODS: This was a retrospective cohort study of individuals with state health insurance at the Moscow Ambulatory Center. The cohorts included 41,444 persons vaccinated with Sputnik V, 15,566 survivors of COVID-19, and 71,377 non-immune persons. The deaths of patients that occurred from June 1, 2021, to August 31, 2021, were analyzed. RESULTS: Overall (0.39 % vs. 1.92 %; p < 0.001), COVID-19-related (0.06 % vs. 0.83 %; p < 0.001), and non-COVID mortality (0.33 % vs. 1.09 %; p < 0.001) was lower among vaccinated individuals than among non-immune individuals. The efficacy of vaccination against death from COVID-19 was 96 % [95 % CI 91-98 %] in the general population, 100 % among those aged 18-50 years, 97 % [95 % CI 76-100 %] among those aged 51-70 years, 98 % [95 % CI 90-100 %] among those aged 71-85 years, and 88 % [95 % CI 49-97 %] among those aged > 85 years. CONCLUSION: COVID-19 vaccination with Sputnik V is associated with a decrease in overall and COVID-19-related mortality and is not with increased non-COVID mortality.
Subject(s)
COVID-19 Vaccines , COVID-19 , Humans , Retrospective Studies , SARS-CoV-2 , COVID-19/prevention & control , VaccinationABSTRACT
BACKGROUND AND AIM: Dialysis patients are a high-risk population and have a reduced immune response to vaccination against SARS-CoV-2. The aim of this study was to assess the humoral response to homologous Gam-COVID-Vac (Sputnik V) and heterologous Sputnik V/mRNA-1273 (Moderna) vaccination in dialysis patients. The vaccination scheme depended on dose availability and the prioritization of risk populations as established by the Argentine Ministry of Health. METHODS: Previous COVID-19 infection was determined in symptomatic patients. Binding IgG antibodies against the spike (S) receptor-binding domain (RBD) of SARS-CoV-2 (anti-S-RBD) concentration was assessed between 3 and 16 weeks after the boost dose. Anti-S-RBD antibodies were quantified using the Abbott Diagnostics SARS-CoV-2 IgG II Quant chemiluminescent microparticle immunoassay (CMIA) on an Architect i2000 SR and an Alinity I analyzer (Abbott Diagnostics, Abbott Park, Illinois, USA). To standardize the results to WHO binding antibody units (BAU), a correction factor for Abbott arbitrary units (AU) was applied where 1 BAU/mL equals 0.142 AU, as previously established by Abbott with the WHO international standard NIBSC 20-136. Following the manufacturer's recommendations, samples were considered reactive for anti-S-RBD when titers were above 50 AU/mL (7.2 BAU/mL). An 80% protective effect (PROT-80) against symptomatic SARS-CoV-2 infection was assumed when anti-S-RBD titers were 506 BAU/ml or higher. Charlson Comorbidity Index (CCI) score was classified as mild = 1-2, moderate = 3-4, and severe ≥ 5. Side effects were evaluated until day 7 by patients´ self-reported questionnaire. RESULTS: One hundred seven participants were enrolled [n = 84 homologous (SpV/SpV), nn 23 heterologous (SpV/Mod)]. Median (IQR) age was 64 (50-75) years old and 79 (73.8%) were male. Additionally, 19 (22.6%) of the SpV/SpV and 4 (17.4%) of the SpV/Mod group had a prior confirmed SARS-CoV-2 infection (p = 0.589). In the overall population, 103 patients reached seroconversion (96.3%). Anti-S-RBD IgG median titers (IQR) were higher in the heterologous [1222 (288-5680) BAU/mL] than in the homologous scheme [447 (100-1551) BAU/mL], p = 0.022. In a linear model adjusted for age, gender, days from first vaccination to boost dose and days from the boost dose to the anti-S-RBD IgG determination, previous SARS-COV-2 infection (B: 2062.2; CI95: 1231.8-2892.6; p < 0.001), and SpV/Mod vaccination scheme (B: 1294.6; CI95: 435.58-2147.6; p = 0.003) were independently associated with anti-S-RBD levels. Finally, a higher frequency of adverse effects was associated with the heterologous scheme, although they were well tolerated by all individuals. CONCLUSIONS: The present study provides evidence that the homologous SpV/SpV and heterologous SpV/Mod schemes showed good efficacy and safety in patients on chronic dialysis. These results could be useful for designing future vaccination strategies, especially aimed at this risk group.
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Introduction. In the context of a pandemic of a new coronavirus infection (COVID-19), research on the peculiarities of the formation of an immune response to SARS-CoV-2 in patients who have been ill and vaccinated is of particular relevance. However, most studies are currently devoted to evaluating only the humoral link of immunity, and its cellular component remains insufficiently studied. The aim of the study was to evaluate the features of the formation and changes of the T-cell link of immunity in patients with a new coronavirus infection and vaccinated against this disease. Materials and methods. The study was performed on the basis of the clinical and diagnostic laboratory of the European Medical Center "UMMC-Health "LLC. Specific T-cell immunity was evaluated using ELISPOT technology. In the course of the study, 72 blood samples of employees of medical organizations were analyzed, including 26 from those who had a new coronavirus infection, 23 from persons who were intact according to COVID-19 before vaccination and 23 from the same employees after vaccination (<<Gam-Covid-Vac>>). In addition, each of the study participants was examined to determine specific class G antibodies (IgG) by solid-phase enzyme immunoassay using SARS-CoV-2-IgG-ELISA-BEST test systems (manufactured by VECTOR-BEST JSC). Results and discussion. In the group of patients (26 people), T-lymphocytes capable of specifically reacting to SARSCoV-2 antigens were detected in 100% of cases, even in individuals with IgG elimination. It should be noted that the response was more pronounced when meeting with M-and N-pepdids, compared with S-protein. 22 out of 23 COVID-19 intact individuals had no T-cell immunity to coronavirus infection before vaccination, but one employee had a response to 3 proteins-M, N, S, which indicates that he had previously encountered the SARS-CoV-2 virus. After vaccination with the drug "Gam-Covid-Vac", 22 (95.6%) employees revealed a T-cell response, while 21-only to S-protein, and an employee with a previously detected immune response-after vaccination, the response to M -, N-proteins remained almost at the same level, and the cellular response to S-peptide doubled. Conclusion. Thus, based on the results of the study, important materials were obtained on the peculiarities of the formation of a specific T-cell immune response to a new coronavirus infection. The obtained data provide a broader understanding of the immune response in new coronavirus infection in patients who have been ill and vaccinated and can be used in the future when planning preventive and anti-epidemic measures.Copyright © 2022 Interregional public organization Association of infectious disease specialists of Saint-Petersburg and Leningrad region (IPO AIDSSPbR). All rights reserved.
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Aim. To assess the tolerability of vaccination with the first component of Gam-COVID-Vac (Sputnik V), the frequency and nature of adverse events following immunization (AEFI) depending on gender, age, obesity, and chronic diseases. Material and Methods. The study included male and female patients who received the first component of the Gam-COVID-Vac vaccine at MSU Medical Center. Subsequently, after 14 days, a remote survey of respondents was conducted to collect the data regarding the development of adverse events requiring the use of drug treatment or medical care. Results. The study included 732 participants. Two-thirds of the respondents (65.8%) reported the development of AEFI: pain at the injection site (46.9%), fever (25.5%), muscle pain (29.9%), and headache (27%). At the same time, women noted the occurrence of AEFI more often than men (72.4% vs 57.5%, p < 0.05), and AEFI duration was also longer. Patients over 60 years of age reported less fever than patients under 40 years of age (21.0% vs 31.1%;p < 0.031). Young age and female gender were independent predictors of AEFI after vaccination with the first component of the Sputnik V vaccine. Obesity and a history of reported chronic non-infectious diseases did not correlate with the occurrence of AEFI. Conclusion. Adverse events after the administration of the first component of Gam-COVID-Vac (Sputnik V) were of short duration and were easily tolerated by both young and old patients. © 2022 Tomsk State University. All rights reserved.
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Relevance. Many countries around the world are developing effective vaccines against SARS-CoV-2. The measure of the effectiveness of the vaccination process has traditionally been antibody production. The frequency and intensity of adverse reactions is also an important factor in making a decision regarding a vaccine. This study presents the results of the evaluation of the formation of humoral immunity and the occurrence of reactions in response to the administration of Sputnik V (Gam-COVID-Vac), RF, and Sinopharm (BBIBP-CorV), PRC. Aim. Analyze immunogenicity and reactogenicity of COVID-19 vaccines used in the Republic of Belarus (Sputnik V and Sinopharm). Materials and methods. Evaluation of postvaccination immune response by enzyme immunoassay and differential enzyme immunoassay for class G immunoglobulins to S-and N-proteins SARS-CoV-2. Blood plasma of the study participants was used as biological material. Blood sampling was performed 3 times: immediately before the first vaccine dose, on day 42, and 6 months after the first vaccine dose. To evaluate the frequency and intensity of postvaccination reactions, study participants were questioned. Results. At 42 days after administration of both vaccines, antibody levels are rising, with a significantly higher quantitative IgG count for the Sputnik V vaccine. This trend is also observed 6 months after the first dose of both vaccines, both among those previously infected with SARS-CoV-2 and those without a history of COVID-19. The comparison of Sputnik V and Sinopharm vaccine groups in terms of IgG (BAU/ml) levels to S-and N-proteins revealed a statistically significant difference in IgG levels to S-protein: the Sputnik V vaccine group had significantly higher IgG levels to S-protein than the Sinopharm vaccine group (p = 0.0000196). The incidence of adverse reactions in this study was 45%. All reactions noted were mild to moderate in severity. The most common were soreness and redness at the injection site, elevated body temperature, and a combination of several reactions. The increased body temperature after vaccination was more common among those vaccinated with the Sputnik V vaccine. Conclusion. Compared to Sinopharm, Sputnik V vaccine produces higher antibody level. Adverse reactions were observed in both vaccinated groups. However, significant statistical differences were found with regard to fever in the Sputnik V vaccine group, which occurred more frequently. © 2023, Numikom. All rights reserved.
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In November 2020, the Armed Forces of the Russian Federation began mass immunisation of the personnel with Gam-COVID-Vac (Sputnik V), the first Russia vaccine against the new coronavirus infection (COVID-19). Thus, it became necessary to assess post-vaccination antibody levels and the duration and intensity of humoral immunity to COVID-19. The aim of the study was to investigate the immunogenicity and efficacy of Gam-COVID-Vac in military medical staff after vaccination. Material(s) and Method(s): the authors determined the presence of specific antibodies in the serum of individuals immunised with Gam-COVID-Vac (477 volunteers) and COVID-19 convalescents (73 patients), using virus neutralisation (VN), enzyme-linked immunosorbent assay (ELISA) with reagent kits by several manufacturers, and immunoblotting. The results of the study were evaluated using analysis of variance. Result(s): VN detected virus neutralising antibodies in 90.7% of vaccinated subjects;ELISA, in 95.4%. Both VN and ELISA showed lower antibody levels in the vaccinated over 50 years of age. ELISA demonstrated a significantly higher concentration of anti-SARS-CoV-2 spike IgG in the Gam-COVID-Vac group than in the COVID-19 convalescent group. The correlation between antibody detection results by VN and ELISA was the strongest when the authors used their experimental reagent kit for quantitative detection of virus neutralising antibodies by competitive ELISA with the recombinant human ACE2 receptor. Having analysed the time course of neutralising antibody titres, the authors noted a significant, more than two-fold decrease in geometric means of the titres three months after administration of the second vaccine component. Conclusion(s): the subjects vaccinated with Gam-COVID-Vac gain effective humoral immunity to COVID-19. The decrease in titres indicates the need for revaccination in 6 months.Copyright © 2023 Safety and Risk of Pharmacotherapy. All rights reserved.
ABSTRACT
The clinical case describes the difficulties of differential diagnosis of polyneuropathy that developed, after Gam-Covid-Vac vaccination on the background, of combined, infectious pathology (HIV infection, tick-borne borreliosis, COVID-19) in a young woman. It is shown that various infectious and noninfectious diseases with similar clinical symptoms (peripheral nervous system, affliction.) occurring simultaneously in one patient can significantly affect each other's course and. complicate the establishment of the true cause of polyneuropathy. It should, be noted, that in this example, the establishment of a final diagnosis was carried out collectively, by consensus, and. was based, on the effectiveness of etiotropic (antibacterial) treatment, which in fact was an exjuvantibus therapy option, which made it possible to establish the most probable etiology of polyneuropathy -tick-borne borreliosis. In turn, HIV infection and. possibly vaccination, according to the authors, could, cause immunosuppression, which, affected, the degree of dissemination, of Borrelia burgdorferi. It is also likely that the insufficient immune response in combination. with the cascade plasma filtration session affected the initial dubious results of the serological tests, which further complicated. the diagnosis.Copyright © 2022 Authors. All rights reserved.
ABSTRACT
The clinical case describes the difficulties of differential diagnosis of polyneuropathy that developed, after Gam-Covid-Vac vaccination on the background, of combined, infectious pathology (HIV infection, tick-borne borreliosis, COVID-19) in a young woman. It is shown that various infectious and noninfectious diseases with similar clinical symptoms (peripheral nervous system, affliction.) occurring simultaneously in one patient can significantly affect each other's course and. complicate the establishment of the true cause of polyneuropathy. It should, be noted, that in this example, the establishment of a final diagnosis was carried out collectively, by consensus, and. was based, on the effectiveness of etiotropic (antibacterial) treatment, which in fact was an exjuvantibus therapy option, which made it possible to establish the most probable etiology of polyneuropathy -tick-borne borreliosis. In turn, HIV infection and. possibly vaccination, according to the authors, could, cause immunosuppression, which, affected, the degree of dissemination, of Borrelia burgdorferi. It is also likely that the insufficient immune response in combination. with the cascade plasma filtration session affected the initial dubious results of the serological tests, which further complicated. the diagnosis.Copyright © 2022 Authors. All rights reserved.
ABSTRACT
Currently, as the SARS-CoV-2 pandemic evolves, there has been increasingly more attention paid to building natural and vaccine-induced immunity against SARS-CoV-2 and related disease known as COVID-19. Widespread preventive vaccination plays an important role in effectively protecting people from viral infections and can reduce national economic costs. Purpose - to study peripheral blood cell subset composition and magnitude of humoral response in vaccinated Gam-COVID-Vac subjects. The prospective study included 352 patients, of which 194 (119 women and 75 men) underwent an immunogram study and assessed level of anti-SARS-CoV-2 antibodies. In patients, the study of the lymphocyte subset composition and estimation of anti-SARS-CoV-2 antibodies was carried out at two time points - prior to vaccination and 90 days after inoculated component 1 of the Gam-COVID-Vac vaccine. In general, vaccination was well tolerated by patients, with no serious adverse events after immunization. The reaction to the vaccine (fever, malaise, headache, local reactions) was short-term (1-2 days) and more often noted after inoculated vaccine component 2. Comparatively analyzed immunogram parameters in females before and after vaccination revealed increased relative level of T-lymphocytes (CD3+), T-helper cell subset (CD3+CD4+), increased absolute and relative level of activated CD3+CD25+ T-lymphocytes, but decreased absolute and relative level of natural killer (CD3-CD56+CD16+) and natural killer T-cell (CD3+CD56+CD16+) cell subsets as well as decreased CD147 receptor expression on T-lymphocytes. Similar patterns were also found while examining the immunogram in males exepting increased level of lymphocytes and lowered CD147 expression on both T- and B-lymphocytes. No changes in the parameters of the immune T-cell arm was found. The high efficacy of the vaccine was confirmed by development of SARS-CoV-2-specific class G antiviral antibodies in 97.5% and 92.3% of vaccinated females and males, respectively. The data obtained evidence that: 1) vaccination induces a specific humoral immune response determined three months post-vaccination, and 2) it caused no serious disturbances in the immune system functioning, which could be reflected in the peripheral blood lymphocyte subset composition. Thus, the data presented allow to conclude that Gam-COVID-Vac is effective vaccine against SARS-CoV-2 infection.Copyright © 2022 Saint Petersburg Pasteur Institute. All rights reserved.
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Background: Measuring the level of antibodies produced post-vaccination in response to the SARS-CoV-2 spike protein is considered a strategy for estimating the effectiveness of the COVID-19 vaccines. Objective: To examine the antibody levels among the healthcare workers in different hospitals in Mashhad, Iran after receiving the second dose of Sputnik V. Methods: In this study, we enrolled 230 healthcare workers for evaluating the Gam-COVID-Vac or Sputnik V after the second administration in different hospitals in Mashhad. Antibody levels of spike protein were quantitatively evaluated in a sample of 230 negative RT-PCR tests for the COVID-19 individuals. The analysis has been done based on an immunological assay using enzyme-linked immunosorbent assay (ELISA). The infection history of the subjects and their families was examined through their medical records. Results: Our results demonstrated a significant association between a higher titer of IgG and a previous history of the COVID-19 infection (P<0.001). Moreover, the chance of detecting antibodies titer more than 50 AU/ml was 16.99 in these people which was significantly higher than in people without a history of infection pre-vaccination [%95CI: (7.38,39.12), P<0.001]. Conclusion: This result demonstrates that the efficacy of antibody production is related to the previous history of the SARS-CoV-2 infections. Ongoing monitoring of the level of antibody among vaccinated populations will help evaluating the effect of vaccines on humoral immunity status.
Subject(s)
COVID-19 , Humans , COVID-19/prevention & control , COVID-19 Vaccines , SARS-CoV-2 , Antibodies , Health Personnel , Antibodies, ViralABSTRACT
The course of the COVID-19 pandemic has been critically altered by the availability of vaccines. To assess the risk of COVID-19 in the vaccinated, as compared to the unvaccinated population, as well as the comparative effectiveness of the BBIBP-CorV (Sinopharm), BNT162b2 (Pfizer/BioNTech), Gam-COVID-Vac (Sputnik V) and ChAdOx1 (AstraZeneca) vaccines in the prevention of clinical infection, we carried out a retrospective study of the incidence of clinical COVID-19 in the Belgrade city municipality of Vozdovac among both vaccinated and unvaccinated individuals during a 4-month period between 1 July and 31 October 2021. The study included all individuals with a symptomatic infection confirmed by a positive PCR and/or antigen test. Only those who received two vaccine doses were considered as vaccinated. The results showed that of the Vozdovac population of 169,567, a total of 81,447 (48%) individuals were vaccinated by the end of the study. Vaccination coverage increased with age, ranging from 1.06% in those below age 18, to even 78.8% in those above 65 years of age. More than one half (57.5%) of all those vaccinated received BBIBP-CorV, while 25.2% received BNT162b2, 11.7% Gam-COVID-Vac and 5.6% ChAdOx1. The overall risk of infection of the vaccinated vs. the unvaccinated was 0.53 (95% CI 0.45-0.61). Compared to the incidence of COVID-19 of 8.05 per 1000 in the unvaccinated population, the relative risk in the vaccinated was 0.35 (95% CI 0.3-0.41). The overall VE was 65%, differing widely among age groups and by vaccine. VE was 79% for BNT162b2, 62% for BBIBP-CorV, 60% for ChAdOx1 and 54% for Gam-COVID-Vac. The VE for BBIBP-CorV and BNT162b2 increased with age. The obtained results demonstrate a significant overall effectiveness of anti-COVID-19 vaccination, which, however, varied significantly among the analyzed vaccines, and was the highest for BNT162b2.
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Millions of people have been vaccinated with Gam-COVID-Vac but fine specificities of induced antibodies have not been fully studied. Plasma from 12 naïve and 10 coronavirus disease 2019 (COVID-19) convalescent subjects was obtained before and after two immunizations with Gam-COVID-Vac. Antibody reactivity in the plasma samples (n = 44) was studied on a panel of micro-arrayed recombinant folded and unfolded severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins and 46 peptides spanning the spike protein (S) and by immunoglobulin G (IgG) subclass enzyme-linked immunosorbent assay (ELISA). The ability of Gam-COVID-Vac-induced antibodies to inhibit binding of the receptor-binding domain (RBD) to its receptor angiotensin converting enzyme 2 (ACE2) was investigated in a molecular interaction assay (MIA). The virus-neutralizing capacity of antibodies was studied by the pseudo-typed virus neutralization test (pVNT) for Wuhan-Hu-1 and Omicron. We found that Gam-COVID-Vac vaccination induced significant increases of IgG1 but not of other IgG subclasses against folded S, spike protein subunit 1 (S1), spike protein subunit 2 (S2), and RBD in a comparable manner in naïve and convalescent subjects. Virus neutralization was highly correlated with vaccination-induced antibodies specific for folded RBD and a novel peptide (i.e., peptide 12). Peptide 12 was located close to RBD in the N-terminal part of S1 and may potentially be involved in the transition of the pre- to post-fusion conformation of the spike protein. In summary, Gam-COVID-Vac vaccination induced S-specific IgG1 antibodies in naive and convalescent subjects in a comparable manner. Besides the antibodies specific for RBD, the antibodies induced against a peptide close to the N-terminus of RBD were also associated with virus-neutralization.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/metabolism , Epitopes , Antibodies, Neutralizing , Antibodies, Viral , Protein Subunits , Spike Glycoprotein, Coronavirus/metabolism , Antibody Formation , Immunoglobulin GABSTRACT
Currently, as the SARS-CoV-2 pandemic evolves, there has been increasingly more attention paid to building natural and vaccine-induced immunity against SARS-CoV-2 and related disease known as COVID-19. Widespread preventive vaccination plays an important role in effectively protecting people from viral infections and can reduce national economic costs. Purpose - to study peripheral blood cell subset composition and magnitude of humoral response in vaccinated Gam-COVID-Vac subjects. The prospective study included 352 patients, of which 194 (119 women and 75 men) underwent an immunogram study and assessed level of anti-SARS-CoV-2 antibodies. In patients, the study of the lymphocyte subset composition and estimation of anti-SARS-CoV-2 antibodies was carried out at two time points - prior to vaccination and 90 days after inoculated component 1 of the Gam-COVID-Vac vaccine. In general, vaccination was well tolerated by patients, with no serious adverse events after immunization. The reaction to the vaccine (fever, malaise, headache, local reactions) was short-term (1-2 days) and more often noted after inoculated vaccine component 2. Comparatively analyzed immunogram parameters in females before and after vaccination revealed increased relative level of T-lymphocytes (CD3+), T-helper cell subset (CD3+CD4+), increased absolute and relative level of activated CD3+CD25+ T-lymphocytes, but decreased absolute and relative level of natural killer (CD3-CD56+CD16+) and natural killer T-cell (CD3+CD56+CD16+) cell subsets as well as decreased CD147 receptor expression on T-lymphocytes. Similar patterns were also found while examining the immunogram in males exepting increased level of lymphocytes and lowered CD147 expression on both T- and B-lymphocytes. No changes in the parameters of the immune T-cell arm was found. The high efficacy of the vaccine was confirmed by development of SARS-CoV-2-specific class G antiviral antibodies in 97.5% and 92.3% of vaccinated females and males, respectively. The data obtained evidence that: 1) vaccination induces a specific humoral immune response determined three months post-vaccination, and 2) it caused no serious disturbances in the immune system functioning, which could be reflected in the peripheral blood lymphocyte subset composition. Thus, the data presented allow to conclude that Gam-COVID-Vac is effective vaccine against SARS-CoV-2 infection.
ABSTRACT
Since its initial detection in Brazil in February 2020, SARS-CoV-2 and the associated COVID-19 pandemic have continued to devastate Latin America. Specific comorbidities, as well as sociodemographic and lifestyle factors that may be more prevalent in underserved areas, have been identified as risk factors for COVID-19 infection or associated adverse outcomes. Dynamics of infections and deaths in Latin America have varied by country and temporally, as has SARS-CoV-2 variant prevalence; however, more recently, the Delta and subsequent Omicron variants have become ubiquitous. Successful pandemic responses have involved robust infection mitigation measures, testing, and smart deployment of healthcare resourcing. While in some Latin American countries up to 90% of the population is fully vaccinated (i.e., 2 doses) against COVID-19, other countries have failed to reach the World Health Organization's 70% target. Continued focus on comprehensive surveillance, strategies to maximize vaccine availability and uptake, and mitigation of collateral damage on other aspects of public health and social services are critical for managing the COVID-19 pandemic. This review summarizes the COVID-19 experience in Latin America, including epidemiology and vaccination. Key learnings and future considerations for the ongoing pandemic response are also discussed.
ABSTRACT
The COVID-19 pandemic has required extensive research on the new coronavirus SARS-CoV-2 and the creation of new highly effective vaccines. The presence of T-cells in the body that respond to virus antigens suggests adequate antiviral immunity. We investigated T-cell immunity in individuals who recovered from mild and moderate COVID-19 and in individuals vaccinated with the Gam-COVID-Vac combined vector vaccine. The ELISPOT method was used to determine the number of T-cells responding with IFN-γ synthesis to stimulation by peptides containing epitopes of the S-protein or N-, M-, ORF3, and ORF7 proteins, using peripheral blood mononuclear cells (PBMCs). At the same time, the multiplex method was used to determine the accumulation of IFN-γ and other cytokines in the culture medium. According to the data obtained, the proportion of positive conclusions about the T-cell immune response to SARS-CoV-2 antigens in control, recovered, and vaccinated individuals was 12%, 70%, and 52%, respectively. At the same time, more than half of the vaccinated individuals with a T-cell response were sensitized to the antigens of N-, M-, ORF3, and ORF7 proteins not produced by Gam-COVID-Vac, indicating a high likelihood of asymptomatic SARS-CoV-2 infection. Increased IFN-γ release by single sensitized T-cells in response to specific stimulation in recovered and vaccinated individuals did not result in the accumulation of this and other cytokines in the culture medium. These findings suggest a balance between cytokine production and utilization by immunocompetent cells as a prerequisite for providing a controlled cytokine signal and avoiding a "cytokine storm".