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This study was aimed at evaluating the changes in the antibody titers and neutralization ability before and after inoculation with an mRNA COVID-19 vaccine (Pfizer, USA) among healthcare professionals (HCPs) in Japan. A total of 221 HCPs were enrolled and their blood samples were collected at three time points: (1) before vaccination, (2) 3 weeks after the first dose, and (3) 3 weeks after the second dose. The titers of anti-SARS-CoV-2 Spike protein IgG antibody were measured in all the samples using VITROS-Anti-SARS-CoV-2 S1 Quant IgG Antibody (CLEIA, Ortho-Clinical Diagnostics, Inc.), and the surrogate Virus Neutralization Test (sVNT) (ELISA, GenScript, USA) was performed in the samples obtained after the vaccination. The anti-SARS-CoV-2 IgG titers were (1) median: 0.16;Interquartile (IQR): 0.10-0.27, (2) median: 250;IQR: 99.5-466 and (3) median: 2,400;IQR: 1,480-3,950, respectively, at the three time-points. Our study also revealed the relationship between the anti-SARS-CoV-2 IgG antibody titer and the antibody neutralization activity.
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The aim of the work: To map the prevalence of antibodies against SARS-CoV-2 among employees of the Faculty Thomayer Hospital in Prague after the first wave of the covid-19 disease. A large number of people with proven covid-19 infection were treated and hospitalized in the first wave at the Thomayer University Hospital. Material and methods: Voluntary study based on questionnaire survey and determination of total antibodies (ECLIA, Roche) and individual classes of immunoglobulins (ELISA IgG and IgA, Euroimmun).
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Aim: The presence of neutralizing antibodies (NAbs) is an indicator of protective immunity for most viral infections. This study investigated the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies NAbs (IgM & IgG) following vaccination with three common potential vaccines (Pfizer, AstraZeneca and Sino pharm), in Nasiriya city /south of Iraq. Methods. From September 2021 to April 2022.158 participants who had completed COVID-19 vaccination (50 persons for each) were recruited and tested using Covid-19 neutralizing antibody kits, for NAbs evaluation. Results. Majority of the participants were 21-40 years old of age. NAbs were observed in 100% of enrolled individuals (vaccinated or not) but with significant difference in the IgM and IgG titers in correlate to the vaccine type, but there weren't with other demographic factors effect. Nine days after second vaccine dose, spike protein neutralizing antibody levels were two-fold higher of IgM and 5-fold higher of IgG, exceeding titers of non-vaccinated SARS-CoV-2-naive control. Pfizer vaccine type against COVID-19 gave the highest IgM and IgG titers during the 6 months' trial, with the lowest declining rate. AstraZeneca vaccine type provided an intermediate IgM and IgG titer with a rapid declining rate, while Sino pharm vaccine offered a low IgM and IgG titers with slowly decreasing rate with time.
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To evaluate the effect of colloidal gold immunochromatographic assay (GCIA) combined with chemiluminescent immunoassay (CLIA) in reducing the false positive of antibodies against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Thirty-three serum samples from 19 patients with SARS-CoV-2 infection at different times, and 55 serum samples from 55 patients not infected with SARS-CoV-2. but infected instead with other pathogens or suffering from autoimmune diseases were collected from the Affiliated Hospital of North Sichuan Medical College and Nanchong Central Hospital from 22 January to 5 March 2020. Serum IgM and IgG against SARS-CoV-2 were detected by GICA and CLIA respectively, and the results were analyzed. The sensitivity of GCIA for detection of IgM and IgG against SARS - CoV - 2 was 100.0% and 94.74%. respectively, values that were similar with those for CLIA (92.86% and 100.0%) (P = 1.000). The specificity of GCIA for IgM and IgG against SARS-CoV-2 was 70.91% and 74.55% respectively, which was significantly lower than that of CLIA (98.18% and 89.09%) (P < 0.01). The results of IgM and IgG against SARS-CoV-2 detected by the two methods were consistent (P=0.000) . and their Kappa was 0.434 and 0.406. respectively. Analyses of ROC curves showed that the AUC of IgM and IgG against SARS-CoV-2 detected by GCIA was 0.855 and 0.846. respectively, which was significantly lower than that of CLIA (0.955 and 0.945, respectively) (PC0.05). The sensitivity of combined detection of IgM and IgG against SARS -CoV-2 was 92.86% and 94.74%. and the specificity was 100.0% and 100.0%, respectively. Analyses of ROC curves showed that the AUC of combined detection of IgM and IgG against SARS-CoV-2 was 0.964 and 0.974. respectively, which was higher titan that of each method alone. GCIA combined with CLIA can improve the specificity of detection of IgM and IgG against SARS-CoV-2, which may merit clinical application.
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Introduction: Sleep disorders and sleep deprivation induces decreased antibody response following vaccination for different viral diseases (including H1N1, influenza and hepatitis A). The same has been speculated for COVID-19. This study aimed to assess whether obstructive sleep apnea (OSA) reduces antibody levels after COVID-19 vaccination among older adults.
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This study aimed to evaluate the application and diagnostic efficacy of two different colloidal gold kits for the detection of 2019-nCoV immunoglobulin M antibody (anti-IgM) and immunoglobulin G antibody (anti-IgG) in Beijing, a low endemic area, and to guide the rational clinical application. The sera of 29 patients with confirmed novel coronavirus pneumonia (COVID-19) and 19 411 patients from the non-infected screening population were selected to evaluate the sensitivity, specificity and false-positive rate of the 2019-nCoV antibody test kits from Zhuhai Lizhu and Tangshan Innotek using colloidal gold immunochromatography. The sensitivity of Inotec 2019-nCoV was slightly higher than that of Lizhu 2019-nCoV, with a sensitivity of 58.62% and 55.17%, respectively;the specimen collection time of the all-negative group was significantly less than that of the antibody-positive group (P < 0.05);the false-positive rate of the two reagents in the low-prevalence area was 0.16%, and the false-positive rate of 2019-nCoV IgG was higher in Inotec than in Lizhu. The false positive rate for 2019-nCoV IgM was significantly higher than that for IgG for the same brand (Inotec ?2=14.756 09, P=0.000 0;Lizhu ?2=27.492 62, P=0.000). Conclusion The 2019-nCoV antibody test is rapid, simple and easy to perform, with high specificity, and can be used as a rapid screening indicator for new crowns;the specificity, correctness and negative predictive value of the two kits are good, and the application of the other kit for retesting when a positive result occurs can reduce the false positive rate of informing the clinic;the application and analysis of positive reports of new crown antibodies should be combined with the endemic area and clinical comprehensive judgment.
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Objective: To understand the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) specific IgM, IgC and IgA responses in corona Virus disease 2019(COVID-19) patients. Method: The SARS-CoV-2-specific IgM and IgG levels were determined by the enzyme-linked immunosorbent assay while IgA 1evels were detected by the chemiluminescence immune detection systems.
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This study sought to evaluate the effects of two vaccine doses and the extent of SARS-CoV-2 infection among healthcare workers. We measured immunoglobulin G antibody titers against SARS-CoV-2 nucleocapsid and spike protein among healthcare workers at Gunma University Hospital. In March 2021, prior to BNT-162b2 vaccination, two of 771 participants were seropositive for nucleocapsid and spike protein, whereas 768 were seronegative. The remaining one participant was seropositive for nucleocapsid protein but seronegative for spike protein. A total of 769 participants were seropositive for spike protein after two vaccination doses. The two seropositive participants prior to vaccination showed the highest antibody titers after the second vaccination. They were probably infected with SARS-CoV-2 without clinical symptoms before March 2021. Four weeks after the second vaccination, a younger age was associated with higher antibody titers against SARS-CoV-2 spike protein. Thirty-two weeks after the second vaccination, blood samples were collected from 342 of 769 participants. Antibody titers at 32 weeks after the second vaccination significantly decreased compared with those at 4 weeks after the second vaccination among all age groups. The rate of decrease in antibody titers between 4 and 32 weeks after the second vaccination was greater in the female participants. No sex differences were observed in the antibody titers within each age group. BNT-162b2 vaccination thus induced seroconversion in an age-dependent manner. Serological screening could further establish the likelihood of subclinical SARS-CoV-2 infection.
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This study presents the results of the examination of potential donors of blood and its components for immunoglobulins M and G to patients with coronavirus disease 2019 (COVID-19) living in St. Petersburg. A total of 6782 people aged 18-24 years were evaluated, which accounted for 2.07% of the region's population (326 760 people) of this age group. The study was carried out in the spring and autumn of 2020. A negative result (absence of antibodies) was obtained in 93.5% of the participants. The rates of immunoglobulins M and M + G were 0.58% and 4.18%, respectively, in the spring and autumn. Moreover, the number of participants who had immunoglobulins M and G + M in the autumn period was four times higher than the indicators of the spring period, which indicated greater infection activities in the population during this period. This is most likely due to the active movement of the population in the summer. When comparing the rates of COVID-19 infection and the frequency of occurrence in donors of the same age, markers of human immunodeficiency virus 1 and 2 and hepatitis B and C in 2020 (0.024, 0.012 and 0.13%, respectively) indicate the urgency of the problem of donor selection during blood services, especially during a difficult epidemiological situation because of COVID-19. Along with organizational measures for the selection of donors (e.g., attracting individuals from organized groups in which there are no signs of an unfavorable epidemiological situation to donation), mandatory testing of potential donors for immunoglobulins M and G should be considered.
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Objective: To observe the changes of IgG antibody titers in plasma of convalescent COVID-19 patients before and after methylene blue/photochemical virus inactivation and freezing preservation.
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Background: The COVID-19 pandemic has led to more than 260 million infections and 55 million deaths as of early December 2021, worldwide. Vaccinating people against COVID-19 is considered as he best approach to overcome the pandemic since COVID 19-vaccines are effective and can reduce the risk of getting and spreading the virus. However, their efficacy and safety in patients with underlying disease such as cancers have not been approved yet. Here we report a cohort study on immunogenicity and safety of the inactivated SARS-CoV-2 vaccine (BBIBP-CorV) in patients with breast cancer, who were vaccinated as a part of a national plan for vaccination of patients with special diseases.
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To investigate the characteristics of the nucleic acids of severe acute respiratory syndrome coronavirus (SARS-CoV) -2 and antibodies in different specimens obtained from coronavirus disease 2019 (COVID-19) patients;if a correlation between these parameters and the disease course was present. The throat swabs and stool samples of 39 COVID-19 patients admitted to our hospital were collected in this study. Real-time reverse transcription-quantitative polymerase chain reaction (RT-PCR) was undertaken on throat swabs and stool samples. Peripheral blood was taken and serum levels of immunoglobulin IgM and IgG measured. Results showed That, Throat swabs and stool samples tested positive for the nucleic acid of SARS-CoV-Z, but nucleic acid levels were reduced significantly 15 days after disease onset compared with that upon diagnosis. The Ct value of the nucleic acid test was increased significantly. Serum levels of IgM and IgG were significantly higher than those of healthy people. nucleic acid loads in throat swabs and stool samples as well as serum levels of IgM and IgG were highly correlated with the disease course (r = 0.7387,0.5696, -0.546 and 0.6117,respectively, P < 0.05). In this study nucleic acid loads in throat swabs and stool samples as well as serum levels of IgM and IgG are highly correlated with the course of COVID-19.
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Introduction. SARS-CoV-2 infection have been reported to have a greater mortality rate in adults receiving dialysis, as compared to general population. Hence, vaccination is very important in this vulnerable population group, in order to achieve an acceptable level of immunity. The aim of this study was to compare the level of anti-SARS-CoV-2 anti-spike protein receptor-binding domain IgG neutralizing antibody before and after vaccination with two doses of SinopharmR vaccine, in patients undergoing hemodialysis. Methods. Ninety patients on maintenance in-center hemodialysis received two doses of SinopharmR COVID-19 vaccine with an interval of about 28 days. Anti-SARS-CoV-2 anti-spike protein receptor-binding domain IgG (Anti-RBD) neutralizing antibody was measured with an ELISA kit. All statistical analyses were performed by SPSS-26 software. Results. The absolute mean (+or- SE) change in antibody titer following full-scheduled vaccination was 8.98 +or- 1.49 micro g/mL. The rate of seroconversion was 31.1% after two doses of vaccine. In addition, the rate of seroconversion was higher in those with a history of COVID-19 than in those without a history of COVID-19. Conclusion. Conclusion. The administration of booster doses, doubling of the dose in each episode of vaccination schedule as well as combination of different vaccine platforms are recommended to increase COVID-19 vaccine efficacy in hemodialysis patients.
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Introduction: COVID-19 caused by SARS coronavirus two has halted life across the globe since its emergence in December 2019. Most of the infected persons are asymptomatic or have mild symptoms. Serosurvey is vital for the estimation of the burden of infection. In this context, our study objective is to estimate the Seroprevalence of SARS CoV 2 IgG among the first-year medical students after the first wave in February 2021. Method: A cross-sectional study was conducted among the first-year medical students of Veer Surendra Sai Institute of Medical Sciences and Research. All the students were enrolled, and their data & serum sample was collected. Serum samples were tested for the presence of Anti-Spike IgG. Data were analyzed by using appropriate statistical tests.
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Objective: To analysis the related factors that influenced the elimination of virus in patients with coronavirus disease 2019 (COVID-19), and help with its prevention and control.
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Objective: To determine the serum IgM and IgG antibody levels post-COVID-19 vaccination, and provide scientific evidence for COVID-19 antibody response after vaccination.
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Background and purpose: Coronavirus disease 2019 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, an indirect ELISA method was designed to measure the human IgM and IgG antibodies against SARS-CoV-2. Materials and methods: Protein sequence of nucleocapsid antigen from SARS-CoV-2 was expressed in E. coli BL21 and then was purified by chromatography. The purified protein was confirmed by SDS-PAGE and Western blotting. An indirect ELISA method was designed to measure the specific IgG and IgM antibodies against SARS-CoV-2 using recombinant N protein. The optimized ELISA method was then applied to measure the IgG and IgM antibodies in 61 infected or recovered COVID-19 patients and in 31 healthy controls. Finally, data obtained from the designed ELISA method were compared with those of a commercially approved ELISA kit.
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The pandemic of the novel coronavirus (SARS-CoV-2) infection has seriously threated global public health, a rapid and easy operated method for coronavirus disease (COVID-19) diagnosis is needed. To evaluate the clinical application efficacy of the colloidal gold rapid test kit for detection of the IgM/IgG antibodies to SARS-CoV-2, a total of 304 clinical diagnosed case, 138 health donor (of which 114 showed SARS-CoV-2) viral RNA negative and 64 other fever patients with respiratory symptoms were selected for the study and the plasma or serum samples were tested for both IgM and IgG with the kit. The comparison of the detection coincidence of the samples from whole blood and plasma or serum were also performed;Furthermore, the time distribution of SARS-CoV-2 viral RNA and IgM/IgG antibodies detections were analyzed. The results showed that, of the 304 clinical diagnosed cases, 105 cases were positive for viral RNA detection, among which the detection sensitivity of IgM and IgG antibodies to SARS-CoV-2 by colloidal gold rapid assay was 76.2% (80/105) and 86.6% (91/105), respectively, and the overall coincidence rate of IgM/IgG antibody was 96.1% (101/105);and 73 cases were negative for both nucleic acid and antibody detection. Of the remaining 126 clinical diagnosed cases, the positive rate of IgM and IgG was 69.2% (87/126) and 98.3% (125/126), respectively, and the overall coincidence rate of IgM/IgG antibody was 100% (126/126). In detections for healthy and other fever patients, the specificity of IgM and IgG was 99% (200/202) and 98% (198/202), respectively, and the total coincidence rate of antibody detection results of homologous whole blood and plasma samples was 99%, indicating a high degree of consistency. In this study, the detection assay of SARS-CoV-2 antibodies using colloidal gold method showed satisfactory detection effect, and it could be used for clinical auxiliary diagnosis and epidemiological investigation, which could be applied in a wide range of scenarios and play a valuable role in the prevention and control of SARS-CoV-2 pandemic.
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Objective: To analyze the epidemiological characteristics of a COVID-19 case imported from Nepal in Chongqing of China, and provide evidence for the prevention and control of imported COVID-19.
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Objective: To investigate the level of serum antibodies in COVID-19 patients six months after discharge, and to provide data to evaluate the duration of IgM, IgG and neutralizing antibody titers in the patients.