scholarly journals Performance evaluation of novel fluorescent-based lateral immune flow assay (LIFA) for rapid detection and quantitation of total anti-SARS-CoV-2 S-RBD binding antibodies in infected individuals

2022 ◽  
Author(s):  
Farah M. Shurrab ◽  
Nadin Younes ◽  
Duaa W. Al-Sadeq ◽  
Hamda Qotba ◽  
Laith J. Abu-Raddad ◽  
...  
Keyword(s):  
Quantitative Measurement ◽  
Neutralizing Antibody ◽  
Kappa Statistic ◽  
Protein S ◽  
Rt Pcr ◽  
Qualitative And Quantitative ◽  
Automated Assay ◽  
Quantitative Validation ◽  
Binding Antibody ◽  
Response Post

1.AbstractBackgroundThe vast majority of the commercially available LFIA is used to detect SARS-CoV-2 antibodies qualitatively. Recently, a novel fluorescence-based LIFA test was developed for quantitative measurement of the total binding antibody units (BAU/mL) against the receptor-binding domain of the SARS-CoV-2 spike protein (S-RBD).AimTo evaluate the performance of the fluorescence LIFA Finecare™ 2019-nCoV S-RBD test along with its reader (Model No.: FS-113).MethodsPlasma from 150 RT-PCR confirmed-positive individuals and 100 pre-pandemic samples were tested by FinCare™ to access sensitivity and specificity. For qualitative and quantitative validation of the FinCar™ measurements, the BAU/mL results of FinCare™ were compared with results of two reference assays: the surrogate virus-neutralizing test (sVNT, GenScript, USA), and the VIDAS®3 automated assay (BioMérieux, France).ResultsFinecare™ showed 92% sensitivity and 100% specificity compared to PCR. Cohen’s Kappa statistic denoted moderate and excellent agreement with sVNT and VIDAS®3, ranging from 0.557 (95% CI: 0.32-0.78) to 0.731 (95% CI: 0.51-0.95), respectively. A strong correlation was observed between Finecare™/sVNT (r=0.7, p<0.0001) and Finecare™/VIDAS®3 (r=0.8, p<0.0001).ConclusionFinecare™ is a reliable assay and can be used as a surrogate to assess binding and neutralizing antibody response post-infection or vaccination, particularly in none or small laboratory settings.

scholarly journals Validation of a novel fluorescent lateral flow assay for rapid qualitative and quantitative assessment of total anti-SARS-CoV-2 S-RBD binding antibody units (BAU) from plasma or fingerstick whole-blood of COVID-19 vaccinees

2022 ◽  
Author(s):  
Nadin Younes ◽  
Duaa Walid Al-Sadeq ◽  
Farah Shurrab ◽  
Hadeel Zedan ◽  
Haissam Abou Saleh ◽  
...  
Keyword(s):  
Whole Blood ◽  
Quantitative Measurement ◽  
Pearson Correlation ◽  
Protein S ◽  
Receptor Binding Domain ◽  
Moderate Correlation ◽  
Post Vaccination ◽  
Qualitative And Quantitative ◽  
Rapid Prediction ◽  
Binding Antibody

Background: Limited commercial LFA assays are available to provide a reliable quantitative measurement of the total binding antibody units (BAU/mL) against the receptor-binding domain of the SARS-CoV-2 spike protein (S-RBD). Aim: To evaluate the performance of FinecareTM2019-nCoV S-RBD LFA and its fluorescent reader (FinecareTM-FIA Meter) against the following reference methods (i) The FDA-approved Genscript surrogate virus-neutralizing assay (sVNT), and (ii) three highly performing automated immunoassays: BioMerieux VIDAS, Ortho VITROS, and Mindray CL-900i. Methods: Plasma from 488 vaccinees were tested by all aforementioned assays. Fingerstick whole-blood samples from 156 vaccinees were also tested by FinecareTM. Results and conclusions: FinecareTM showed 100% specificity as none of the pre-pandemic samples tested positive. Equivalent FinecareTM results were observed among the samples taken from fingerstick or plasma (Pearson correlation r=0.9, p<0.0001), suggesting that fingerstick samples are sufficient to quantitate the S-RBD BAU/mL. A moderate correlation was observed between FinecareTM and sVNT (r=0.5, p<0.0001), indicating that FinecareTM can be used for rapid prediction of the neutralization antibody post-vaccination. FinecareTM BAU results showed strong correlation with VIDAS (r=0.6, p<0.0001), and moderate correlation with VITROS (r=0.5, p<0.0001), and CL-900 (r=0.4, p<0.0001), suggesting that FinecareTM be used as a surrogate for the advanced automated assays to measure S-RBD BAU/mL.

scholarly journals A single immunization with a rhabdovirus-based vector expressing severe acute respiratory syndrome coronavirus (SARS-CoV) S protein results in the production of high levels of SARS-CoV-neutralizing antibodies

2005 ◽  
Vol 86 (5) ◽  
pp. 1435-1440 ◽  
Author(s):  
Milosz Faber ◽  
Elaine W. Lamirande ◽  
Anjeanette Roberts ◽  
Amy B. Rice ◽  
Hilary Koprowski ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Protein S ◽  
S Protein ◽  
Cellular Immune Responses ◽  
Glycoprotein G ◽  
Cellular Immune ◽  
Animal Reservoirs ◽  
S Genes

Foreign viral proteins expressed by rabies virus (RV) have been shown to induce potent humoral and cellular immune responses in immunized animals. In addition, highly attenuated and, therefore, very safe RV-based vectors have been constructed. Here, an RV-based vaccine vehicle was utilized as a novel vaccine against severe acute respiratory syndrome coronavirus (SARS-CoV). For this approach, the SARS-CoV nucleocapsid protein (N) or envelope spike protein (S) genes were cloned between the RV glycoprotein G and polymerase L genes. Recombinant vectors expressing SARS-CoV N or S protein were recovered and their immunogenicity was studied in mice. A single inoculation with the RV-based vaccine expressing SARS-CoV S protein induced a strong SARS-CoV-neutralizing antibody response. The ability of the RV-SARS-CoV S vector to confer immunity after a single inoculation makes this live vaccine a promising candidate for eradication of SARS-CoV in animal reservoirs, thereby reducing the risk of transmitting the infection to humans.

scholarly journals Molecular Species of the Alcohol Biomarker Phosphatidylethanol in Human Blood Measured by LC-MS

2009 ◽  
Vol 55 (7) ◽  
pp. 1395-1405 ◽  
Author(s):  
Anders Helander ◽  
Yufang Zheng
Keyword(s):  
Fatty Acid ◽  
Human Blood ◽  
Molecular Species ◽  
Quantitative Measurement ◽  
Selected Ion Monitoring ◽  
Blood Samples ◽  
Qualitative And Quantitative ◽  
Ms Analysis ◽  
Alcohol Biomarker ◽  
Product Ions

Abstract Background: The alcohol biomarker phosphatidylethanol (PEth) comprises a group of ethanol-derived phospholipids formed from phosphatidylcholine by phospholipase D. The PEth molecular species have a common phosphoethanol head group onto which 2 fatty acid moieties are attached. We developed an electrospray ionization (ESI) LC-MS method for qualitative and quantitative measurement of different PEth species in human blood. Methods: We subjected a total lipid extract of whole blood to HPLC gradient separation on a C4 column and performed LC-ESI-MS analysis using selected ion monitoring of deprotonated molecules for the PEth species and phosphatidylpropanol (internal standard). Identification of individual PEth species was based on ESI–tandem mass spectrometry (MS/MS) analysis of product ions. Results: The fatty acid moieties were the major product ions of PEth, based on comparison with PEth-16:0/16:0, 18:1/18:1, and 16:0/18:1 reference material. For LC-MS analysis of different PEth species in blood, we used a calibration curve covering 0.2–7.0 μmol/L PEth-16:0/18:1. The lower limit of quantitation of the method was &lt;0.1 μmol/L, and intra- and interassay CVs were &lt;9% and &lt;11%. In blood samples collected from 38 alcohol patients, the total PEth concentration ranged between 0.1 and 21.7 μmol/L (mean 8.9). PEth-16:0/18:1 and 16:0/18:2 were the predominant molecular species, accounting for approximately 37% and 25%, respectively, of total PEth. PEth-16:0/20:4 and mixtures of 18:1/18:1 plus 18:0/18:2 (not separated using selected ion monitoring because of identical molecular masses) and 16:0/20:3 plus 18:1/18.2 made up approximately 13%, 12%, and 8%. Conclusions: This LC-MS method allows simultaneous qualitative and quantitative measurement of several PEth molecular species in whole blood samples.

scholarly journals Quantitative measurement of infectious virus in SARS-CoV-2 Alpha, Delta and Epsilon variants reveals higher infectivity (viral titer:RNA ratio) in clinical samples containing the Delta and Epsilon variants.

2021 ◽  
Author(s):  
Hannah W Despres ◽  
Margaret G Mills ◽  
David J Shirley ◽  
Madaline M Schmidt ◽  
Meei-Li Huang ◽  
...  
Keyword(s):  
Quantitative Measurement ◽  
Infectious Virus ◽  
Viral Rna ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Genome Copy ◽  
Live Virus ◽  
High Degree ◽  
The Relationship ◽  
Rna Levels

ABSTRACT Background Novel SARS-CoV-2 Variants of Concern (VoC) pose a challenge to controlling the COVID-19 pandemic. Previous studies indicate that clinical samples collected from individuals infected with the Delta variant may contain higher levels of RNA than previous variants, but the relationship between viral RNA and infectious virus for individual variants is unknown. Methods We measured infectious viral titer (using a micro-focus forming assay) as well as total and subgenomic viral RNA levels (using RT-PCR) in a set of 165 clinical samples containing SARS-CoV-2 Alpha, Delta and Epsilon variants that were processed within two days of collection from the patient. Results We observed a high degree of variation in the relationship between viral titers and RNA levels. Despite the variability we observed for individual samples the overall infectivity differed among the three variants. Both Delta and Epsilon had significantly higher infectivity than Alpha, as measured by the number of infectious units per quantity of viral E gene RNA (6 and 4 times as much, p=0.0002 and 0.009 respectively) or subgenomic E RNA (11 and 7 times as much, p<0.0001 and 0.006 respectively). Conclusion In addition to higher viral RNA levels reported for the Delta variant, the infectivity (amount of replication competent virus per viral genome copy) may also be increased compared to Alpha. Measuring the relationship between live virus and viral RNA is an important step in assessing the infectivity of novel SARS-CoV-2 variants. An increase in the infectivity of the Delta variant may further explain increased spread and suggests a need for increased measures to prevent viral transmission.

scholarly journals Using a qualitative and quantitative validation methodology to evaluate a drone detection system

ACTA IMEKO ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 20
Author(s):  
Daniela Doroftei ◽  
Geert De Cubber
Keyword(s):  
Detection System ◽  
Weather Conditions ◽  
Careful Consideration ◽  
Technical Aspects ◽  
Operational Conditions ◽  
Qualitative And Quantitative ◽  
Detection Systems ◽  
Quantitative Score ◽  
Validation Procedure ◽  
Quantitative Validation

Now that the use of drones is becoming more common, the need to regulate the access to airspace for these systems is becoming more pressing. A necessary tool in order to do this is a means of detecting drones. Numerous parties have started the development of such drone detection systems. A big problem with these systems is that the evaluation of the performance of drone detection systems is a difficult operation that requires the careful consideration of all technical and non-technical aspects of the system under test. Indeed, weather conditions and small variations in the appearance of the targets can have a huge difference on the performance of the systems. In order to provide a fair evaluation, it is therefore paramount that a validation procedure that finds a compromise between the requirements of end users (who want tests to be performed in operational conditions) and platform developers (who want statistically relevant tests) is followed. Therefore, we propose in this article a qualitative and quantitative validation methodology for drone detection systems. The proposed validation methodology seeks to find this compromise between operationally relevant benchmarking (by providing qualitative benchmarking under varying environmental conditions) and statistically relevant evaluation (by providing quantitative score sheets under strictly described conditions).

scholarly journals Protection of Hamsters Challenged with SARS-CoV-2 Variants of Concern by Two Doses of MVC-COV1901 Vaccine Followed by a Single Dose of Beta Variant Version of MVC-COV1901

2021 ◽  
Author(s):  
Tsun-Yung Kuo ◽  
Chia-En Lien ◽  
Yi-Jiun Lin ◽  
Meei-Yun Lin ◽  
Chung-Chin Wu ◽  
...  
Keyword(s):  
Subunit Vaccine ◽  
Virus Titer ◽  
Neutralizing Antibody ◽  
Protein S ◽  
Protein Subunit ◽  
Live Virus ◽  
The Third ◽  
Severity Of Disease ◽  
Potent Immune Response ◽  
Ancestral Strain

AbstractThe current fight against COVID-19 is compounded by the Variants of Concern (VoCs), which can diminish the effectiveness of vaccines, increase viral transmission and severity of disease. MVC-COV1901 is a protein subunit vaccine based on the prefusion SARS-CoV-2 spike protein (S-2P) adjuvanted with CpG 1018 and aluminum hydroxide. Here we used the Delta variant to challenge hamsters innoculated with S-2P based on the ancestral strain or the Beta variant in two-dose or three-dose regimens. Two doses of ancestral S-2P followed by the third dose of Beta variant S-2P was shown to induce the highest neutralizing antibody titer against live SARS-CoV-2 of the ancestral strain as well as all VoCs. All regimens of vaccination were able to protect hamsters from SARS-CoV-2 Delta variant challenge and reduce lung live virus titer. Three doses of vaccination significantly reduced lung viral RNA titer, regardless of using the ancestral or Beta variant S-2P as the third dose. Based on the immunogenicity and viral challenge data, two doses of ancestral S-2P followed by the third dose of Beta variant S-2P could induce broad and potent immune response against the variants.

scholarly journals SARS-CoV-2 Convalescent Sera Binding and Neutralizing Antibody Concentrations Compared with COVID-19 Vaccine Efficacy Estimates Against Symptomatic Infection

2021 ◽  
Author(s):  
Amy J. Schuh ◽  
Panayampalli S. Satheshkumar ◽  
Stephanie Dietz ◽  
Lara Bull-Otterson ◽  
Myrna Charles ◽  
...  
Keyword(s):  
Vaccine Efficacy ◽  
Neutralizing Antibody ◽  
Published Data ◽  
Symptomatic Infection ◽  
Convenience Sample ◽  
Post Vaccination ◽  
Antibody Assays ◽  
Study Population ◽  
Binding Antibody ◽  
Induced Immunity

Previous vaccine efficacy (VE) studies have estimated neutralizing and binding antibody concentrations that correlate with protection from symptomatic infection; how these estimates compare to those generated in response to SARS-CoV-2 infection is unclear. Here, we assessed quantitative neutralizing and binding antibody concentrations using standardized SARS-CoV-2 assays on 3,067 serum specimens collected during July 27, 2020-August 27, 2020 from COVID-19 unvaccinated persons with detectable anti-SARS-CoV-2 antibodies using qualitative antibody assays. Quantitative neutralizing and binding antibody concentrations were strongly positively correlated (r=0.76, p<0.0001) and were noted to be several fold lower in the unvaccinated study population as compared to published data on concentrations noted 28 days post-vaccination. In this convenience sample, ~88% of neutralizing and ~63-86% of binding antibody concentrations met or exceeded concentrations associated with 70% COVID-19 VE against symptomatic infection from published VE studies; ~30% of neutralizing and 1-14% of binding antibody concentrations met or exceeded concentrations associated with 90% COVID-19 VE. These data support observations of infection-induced immunity and current recommendations for vaccination post infection to maximize protection against symptomatic COVID-19.

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