scholarly journals Evaluation of six commercial SARS-CoV-2 serology assays detecting different antibodies for clinical testing and serosurveillance

2021 ◽  
Author(s):  
Suellen Nicholson ◽  
Theo Karapanagiotidis ◽  
Arseniy Khvorov ◽  
Celia Douros ◽  
Francesca Mordant ◽  
...  
Keyword(s):  
Cell Culture ◽  
Neutralization Test ◽  
Serological Test ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Binding Assays ◽  
Humoral Immune ◽  
A Cell

Abstract Background Serological testing for SARS-CoV-2 complements nucleic acid tests for patient diagnosis and enables monitoring of population susceptibility to inform the COVID-19 pandemic response. It is important to understand the reliability of assays with different antigen or antibody targets to detect humoral immunity after SARS-CoV-2 infection and to understand how antibody (Ab) binding assays compare to those detecting neutralizing antibody (nAb), particularly as we move into the era of vaccines. Methods We evaluated the performance of six commercially available Enzyme-linked Immunosorbent Assays (ELISAs), including a surrogate virus neutralization test (sVNT), for detection of SARS-CoV-2 immunoglobulins (IgA, IgM, IgG), total or nAb. A result subset was compared to a cell culture-based microneutralisation (MN) assay. We tested sera from patients with prior RT-PCR confirmed SARS-CoV-2 infection, pre-pandemic sera and potential cross-reactive sera from patients with other non-COVID-19 acute infections. Results For sera collected > 14 days post-symptom onset, the assay achieving the highest sensitivity was the Wantai total Ab at 100% (95% confidence interval: 94.6-100) followed by 93.1% for Euroimmun NCP-IgG, 93.1% for GenScript sVNT, 90.3% for Euroimmun S1-IgG, 88.9% for Euroimmun S1-IgA and 83.3% for Wantai IgM. Specificity for the best performing assay was 99.5% for the Wantai total Ab and for the lowest performing assay was 97.1% for sVNT (as per IFU). The Wantai Total Ab had the best agreement with MN at 98% followed by Euroimmun S1-IgA, Euro NCP-IgG and sVNT (as per IFU) with (97%, 97% and 95% respectively) and Wantai IgM having the poorest agreement at 93%. Conclusion Performance characteristics of the SARS-CoV-2 serology assays detecting different antibody types are consistent with those found in previously published reports. Evaluation of the surrogate virus neutralization test in comparison to the Ab binding assays and a cell culture-based neutralization assay showed good result correlation between all assays. However correlation between the cell-based neutralization test and some assays detecting Ab’s not specifically involved in neutralization was higher than with the sVNT. This study demonstrates the reliability of different assays to detect the humoral immune response following SARS-CoV-2 infection, which can be used to optimise serological test algorithms for assessing antibody responses post SARS-CoV-2 infection or vaccination.

scholarly journals Evaluation of high-throughput SARS-CoV-2 serological assays in a longitudinal cohort of mild COVID-19 patients: sensitivity, specificity and association with virus neutralization test

2020 ◽  
Author(s):  
Antonin Bal ◽  
Bruno Pozzetto ◽  
Mary-Anne Trabaud ◽  
Vanessa Escuret ◽  
Muriel Rabilloud ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Healthcare Workers ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Serological Tests ◽  
Course Of Disease ◽  
Antibody Titers ◽  
Sensitivity Specificity

BackgroundThe association between SARS-CoV-2 commercial serological assays and virus neutralization test (VNT) has been poorly explored in mild COVID-19 patients.MethodsA total of 439 serum specimens were longitudinally collected from 76 healthcare workers with RT-PCR-confirmed COVID-19. The sensitivity (determined weekly) of nine commercial serological assays were evaluated. Specificity was assessed using 69 pre-pandemic sera. Correlation, agreement and concordance with the VNT were also assessed on a subset of 170 samples. Area under the ROC curve (AUC) was estimated at several neutralizing antibody titers.ResultsThe Wantai Total Ab assay targeting the receptor binding domain (RBD) within the S protein presented the best sensitivity at different times during the course of disease. The specificity was greater than 95% for all tests except for the Euroimmun IgA assay. The overall agreement with the presence of neutralizing antibodies ranged from 62.2% (95%CI; 56.0-68.1) for bioMérieux IgM to 91.2% (87.0-94.2) for Siemens. The lowest negative percent agreement (NPA) was found with the Wantai Total Ab assay (NPA 33% (21.1-48.3)). The NPA for other total Ab or IgG assays targeting the S or the RBD was 80.7% (66.7-89.7), 90.3 (78.1-96.1) and 96.8% (86.8-99.3) for Siemens, bioMérieux IgG and DiaSorin, respectively. None of commercial assays have sufficient performance to detect a neutralizing titer of 80 (AUC<0.76).ConclusionsAlthough some assays presented a better agreement with VNT than others, the present findings emphasize that commercialized serological tests including those targeting the RBD cannot substitute a VNT for the assessment of functional antibody response.

scholarly journals A SARS-CoV-2 Label-Free Surrogate Virus Neutralization Test and a Longitudinal Study of Antibody Characteristics in COVID-19 Patients

2021 ◽  
Author(s):  
Yiqi Ruben Luo ◽  
Cassandra Yun ◽  
Indrani Chakraborty ◽  
Alan H.B. Wu ◽  
Kara L. Lynch
Keyword(s):  
Symptom Onset ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Label Free ◽  
Serum Samples ◽  
Initial Rise ◽  
Igg Avidity ◽  
Antibody Titers

AbstractBackgroundThe laboratory-based methods to measure the SARS-CoV-2 humoral response include virus neutralization tests (VNTs) to determine antibody neutralization potency. For ease of use and universal applicability, surrogate virus neutralization tests (sVNTs) based on antibody-mediated blockage of molecular interactions have been proposed.MethodsA surrogate virus neutralization test established on a label-free immunoassay platform (LF-sVNT). The LF-sVNT analyzes the binding ability of RBD to ACE2 after neutralizing RBD with antibodies in serum.ResultsThe LF-sVNT neutralizing antibody titers (IC50) were determined from serum samples (n=246) from COVID-19 patients (n=113), as well as the IgG concentrations and the IgG avidity indices. Although there is variability in the kinetics of the IgG concentrations and neutralizing antibody titers between individuals, there is an initial rise, plateau and then in some cases a gradual decline at later timepoints after 40 days post-symptom onset. The IgG avidity indices, in the same cases, plateau after the initial rise and did not show a decline.ConclusionsThe LF-sVNT can be a valuable tool in clinical laboratories for the assessment of the presence of neutralizing antibodies to COVID-19. This study is the first to provide longitudinal neutralizing antibody titers beyond 200 days post-symptom onset. Despite the decline of IgG concentration and neutralizing antibody titer, IgG avidity index increases, reaches a plateau and then remains constant up to 8 months post-infection. The decline of antibody neutralization potency can be attributed to the reduction in antibody quantity rather than the deterioration of antibody avidity, a measure of antibody quality.SummaryA surrogate virus neutralization test established on a label-free immunoassay platform (LF-sVNT). Using the LF-sVNT and other assays, 246 serum samples from 113 COVID-19 patients were measured. We observed the time course of antibody characteristics beyond 200 days post-symptom onset.

scholarly journals Evaluation of high-throughput SARS-CoV-2 serological assays in a longitudinal cohort of patients with mild COVID-19: clinical sensitivity, specificity and association with virus neutralization test

2021 ◽  
Author(s):  
Antonin Bal ◽  
Bruno Pozzetto ◽  
Mary-Anne Trabaud ◽  
Vanessa Escuret ◽  
Muriel Rabilloud ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Serological Tests ◽  
Course Of Disease ◽  
Clinical Sensitivity ◽  
Antibody Titers ◽  
Sensitivity Specificity

Abstract Background The association between SARS-CoV-2 commercial serological assays and virus neutralization test (VNT) has been poorly explored in mild patients with COVID-19. Methods 439 serum specimens were longitudinally collected from 76 healthcare workers with RT-PCR-confirmed COVID-19. The clinical sensitivity (determined weekly) of nine commercial serological assays were evaluated. Clinical specificity was assessed using 69 pre-pandemic sera. Correlation, agreement and concordance with the VNT were also assessed on a subset of 170 samples. Area under the ROC curve (AUC) was estimated at 2 neutralizing antibody titers. Results The Wantai Total Ab assay targeting the receptor binding domain (RBD) within the S protein presented the best sensitivity at different times during the course of disease. The clinical specificity was greater than 95% for all tests except for the Euroimmun IgA assay. The overall agreement with the presence of neutralizing antibodies ranged from 62.2% (95%CI; 56.0-68.1) for bioMérieux IgM to 91.2% (87.0-94.2) for Siemens. The lowest negative percent agreement (NPA) was found with the Wantai Total Ab assay (NPA 33% (21.1-48.3)). The NPA for other total Ab or IgG assays targeting the S or the RBD was 80.7% (66.7-89.7), 90.3 (78.1-96.1) and 96.8% (86.8-99.3) for Siemens, bioMérieux IgG and DiaSorin, respectively. None of commercial assays have sufficient performance to detect a neutralizing titer of 80 (AUC&lt;0.76). Conclusions Although some assays show a better agreement with VNT than others, the present findings emphasize that commercialized serological tests including those targeting the RBD cannot substitute a VNT for the assessment of functional antibody response.

scholarly journals Evaluation of Humoral Immune Response after SARS-CoV-2 Vaccination Using Two Binding Antibody Assays and a Neutralizing Antibody Assay

2021 ◽  
Author(s):  
Minjeong Nam ◽  
Jong Do Seo ◽  
Hee-Won Moon ◽  
Hanah Kim ◽  
Mina Hur ◽  
...  
Keyword(s):  
Immune Response ◽  
Severe Acute Respiratory Syndrome ◽  
Humoral Immune Response ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Virus Neutralization Test ◽  
Antibody Assay ◽  
Humoral Immune ◽  
Antibody Assays ◽  
Binding Antibody

The Siemens severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG (sCOVG; Siemens Healthcare Diagnostics Inc., NY, USA) and Abbott SARS-CoV-2 IgG II Quant (CoV-2 IgG II; Abbott Laboratories, Sligo, Ireland), which are automated, quantitative SARS-CoV-2-binding antibody assays, have been recently launched. This study aimed to evaluate the humoral immune response of BNT162b2 and ChAdOx1 nCoV-19 vaccines using sCOVG and CoV-2 IgG II and compare the quantitative values with the results of the GenScript surrogate virus neutralization test (cPASS; GenScript, USA Inc., NJ, USA).

scholarly journals A SARS-CoV-2 Label-Free Surrogate Virus Neutralization Test and a Longitudinal Study of Antibody Characteristics in COVID-19 Patients

2021 ◽  
Author(s):  
Yiqi Ruben Luo ◽  
Cassandra Yun ◽  
Indrani Chakraborty ◽  
Alan H.B. Wu ◽  
Kara L. Lynch
Keyword(s):  
Symptom Onset ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Label Free ◽  
Neutralization Activity ◽  
Initial Rise ◽  
Igg Avidity ◽  
Antibody Titers

Methods designed to measure SARS-CoV-2 humoral response include virus neutralization tests to determine antibody neutralization activity. For ease of use and universal applicability, surrogate virus neutralization tests (sVNTs) based on antibody-mediated blockage of molecular interactions have been proposed. A surrogate virus neutralization test was established on a label-free immunoassay platform (LF-sVNT). The LF-sVNT analyzes the binding ability of SARS-CoV-2 spike protein receptor-binding domain (RBD) to ACE2 after neutralizing RBD with antibodies in serum. The LF-sVNT neutralizing antibody titers (IC50) were determined from serum samples (n=246) from COVID-19 patients (n=113), as well as the IgG concentrations and the IgG avidity indices. Although there was variability in the kinetics of the IgG concentrations and neutralizing antibody titers between individuals, there was an initial rise, plateau and then in some cases a gradual decline at later timepoints after 40 days post-symptom onset. The IgG avidity indices, in the same cases, plateaued after an initial rise and did not show a decline. The LF-sVNT can be a valuable tool in research and clinical laboratories for the assessment of the presence of neutralizing antibodies to COVID-19. This study is the first to provide longitudinal neutralizing antibody titers beyond 200 days post-symptom onset. Despite the decline of IgG concentration and neutralizing antibody titer, IgG avidity index increases, reaches a plateau and then remains constant up to 8 months post-infection. The decline of antibody neutralization activity can be attributed to the reduction in antibody quantity rather than the deterioration of antibody quality, as measured by antibody avidity.

scholarly journals A SARS-CoV-2 surrogate virus neutralization test (sVNT) based on antibody-mediated blockage of ACE2-spike (RBD) protein-protein interaction

2020 ◽  
Author(s):  
Chee Wah Tan ◽  
Wan Ni Chia ◽  
Mark I-C Chen ◽  
Zhiliang Hu ◽  
Barnaby E. Young ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Serological Test ◽  
Rapid Test ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Contact Tracing ◽  
Receptor Protein ◽  
Independent Manner ◽  
Live Virus

Abstract At this critical moment of the international response to the COVID-19 outbreak, there is an urgent need for a robust serological test to detect neutralizing antibodies to SARS-CoV-2. Such a test is not only important for contact tracing, but for determining infection rate, herd immunity and predicted humoral protection. The current gold standard is a virus neuralization test (VNT) requiring live virus and a biosafety level 3 (BSL3) laboratory. On the other hand, the ELISA- or lateral flow-based assays are for the detection of binding antibodies, which does not directly correlate with their neutralizing ability. Here we report a SARS-CoV-2 surrogate virus neutralization test (sVNT) that is designed to detect total neutralizing antibodies in an isotype- and species-independent manner. Our simple and rapid test is based on antibody-mediated blockage of virus-host interaction between the ACE2 receptor protein and the receptor binding domain (RBD) of the viral spike protein. The test has been validated with two COVID-19 patient cohorts in two different countries, achieving 100% specificity and 95-100% sensitivity and is capable of differentiating antibody responses from other known human coronaviruses. Importantly, the sVNT does not require BSL3 containment, thereby making the test immediately accessible to the global community.

scholarly journals Five Commercial Immunoassays for SARS-CoV-2 Antibody Determination and Their Comparison and Correlation with the Virus Neutralization Test

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 593
Author(s):  
Václav Šimánek ◽  
Ladislav Pecen ◽  
Zuzana Krátká ◽  
Tomáš Fürst ◽  
Hana Řezáčková ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Young Patients ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Age Dependent ◽  
Previous Contact ◽  
Dependent Elderly ◽  
Protein Assays ◽  
Antibody Determination

There is an ongoing debate as to whether SARS-CoV-2 antibodies can be found in patients who have recovered from COVID-19 disease. Currently, there is no consensus on whether the antibodies, if present, are protective. Our regular measurements of SARS-CoV-2 antibodies, starting in July 2020, have provided us with the opportunity of becoming acquainted with the five different immunoassays. A total of 149 patients were enrolled in our study. We measured the samples using each immunoassay, then performing a virus neutralization test and comparing the results of SARS-CoV-2 antibodies with this test. We observed that the production of neutralizing antibodies is age-dependent. Elderly patients have a higher proportion of high neutralizing titers than young patients. Based on our results, and in combination with the literature findings, we can conclude that the serological SARS-CoV-2 antibody measurement is a helpful tool in the fight against COVID-19. The assays can provide information about the patient’s previous contact with the virus. Anti-spike protein assays correlate well with the virus neutralization test and can be used in the screening of potential convalescent plasma donors.

scholarly journals Titers of Neutralizing Antibodies against SARS-CoV-2 Are Independent of Symptoms of Non-Severe COVID-19 in Young Adults

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 284
Author(s):  
Hulda R. Jonsdottir ◽  
Michel Bielecki ◽  
Denise Siegrist ◽  
Thomas W. Buehrer ◽  
Roland Züst ◽  
...  
Keyword(s):  
Young Adults ◽  
Neutralizing Antibodies ◽  
Severe Disease ◽  
Humoral Response ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Asymptomatic Infection ◽  
Homogeneous Population ◽  
Humoral Immune ◽  
Antibody Titers

Neutralizing antibodies are an important part of the humoral immune response to SARS-CoV-2. It is currently unclear to what extent such antibodies are produced after non-severe disease or asymptomatic infection. We studied a cluster of SARS-CoV-2 infections among a homogeneous population of 332 predominantly male Swiss soldiers and determined the neutralizing antibody response with a serum neutralization assay using a recombinant SARS-CoV-2-GFP. All patients with non-severe COVID-19 showed a swift humoral response within two weeks after the onset of symptoms, which remained stable for the duration of the study. One month after the outbreak, titers in COVID-19 convalescents did not differ from the titers of asymptomatically infected individuals. Furthermore, symptoms of COVID-19 did not correlate with neutralizing antibody titers. Therefore, we conclude that asymptomatic infection can induce the same humoral immunity as non-severe COVID-19 in young adults.

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