Journal: medRxiv

Article Title: Variant-specific humoral immune response to SARS-CoV-2 escape mutants arising in clinically severe, prolonged infection

doi: 10.1101/2024.01.06.24300890

Figure Lengend Snippet: (a) Duration of hospitalisation (grey bar), time point of first vaccination (asterisc) and detection of SARS-CoV-2 RNA in nasopharyngeal swabs by qRT-PCR. Positive and negative PCR results are indicated by squares and crossed-out squares, respectively. The day of sampling after the initial diagnosis (day 1) is indicated. (b) Time course of the administration and dosage of antiviral therapeutics; the timeline of sampling is indicated in panel d. (c) Relative viral load in nasopharyngeal swabs during the first episode as measured by Ct values of qRT-PCR, for the timeline of sampling see panel d. (d) Mutations detected in S during the first episode. The repeated detection of mutations in consecutive samples is marked with a grey line. GISAID accession numbers of viral genome sequences are given in . The day of sampling after the initial diagnosis (day 1) is indicated.

Article Snippet: We applied the CE/IVD certified cPass TM SARS-CoV-2 Neutralization Antibody Detection Kit (GenScript Biotech, Mainz, Germany) to assess the neutralisation capacity of patient antibodies.

Techniques: Quantitative RT-PCR, Sampling

Journal: Microbiology Spectrum

Article Title: The Comparability of Anti-Spike SARS-CoV-2 Antibody Tests is Time-Dependent: a Prospective Observational Study

doi: 10.1128/spectrum.01402-21

Figure Lengend Snippet: Study flow chart. Anti-Spike(S)-antibody (Ab) assays: Roche S, Abbott S. Infection with SARS-CoV-2 was ruled out by detection of antibodies against the SARS-CoV-2 nucleocapsid (N) using the Roche N ECLIA. W, weeks; sVNT, surrogate virus neutralization test.

Article Snippet: Binding reactivities (Roche, Abbott) were compared to a well-described CE-IVD marked surrogate virus neutralization test (GenScript cPass sVNT) ( , ).

Techniques: Infection, Virus, Neutralization

Journal: Microbiology Spectrum

Article Title: The Comparability of Anti-Spike SARS-CoV-2 Antibody Tests is Time-Dependent: a Prospective Observational Study

doi: 10.1128/spectrum.01402-21

Figure Lengend Snippet: (A) Antibody levels (Roche, Abbott) and percent inhibition in a surrogate virus neutralization test (sVNT) 3 wk (weeks) after the first dose of AZD1222, prebooster (11w after the first dose), and 3 wk postbooster. Dotted lines indicate the test system threshold for positivity (Roche: 0.8 BAU/mL, Abbott 7.1 BAU/mL, sVNT 30%) and, in the case of Roche, the upper level of quantification (2,500 BAU/mL). Green lines represent the group median. ****, P < 0.0001 in Wilcoxon tests. (B) Longitudinal changes of individual Roche, Abbott, and cPass surrogate virus neutralization test (sVNT) results: 3 wk (3 weeks) after the first dose, before the booster dose, and 3 wk after the booster dose. According to the manufacturers, Roche results ≥15 BAU/mL correlate with a positive neutralization test, Abbott results ≥149,1 BAU/mL correspond to a neutralization titer of at least 1:80; 30% inhibition is considered the sVNTs threshold for positivity. Results are, according to the manufacturer, categorized into low (30 to 60%), medium (60 to 90%), and high (>90%) neutralizing capacity (all levels indicated by dotted lines).

Article Snippet: Binding reactivities (Roche, Abbott) were compared to a well-described CE-IVD marked surrogate virus neutralization test (GenScript cPass sVNT) ( , ).

Techniques: Inhibition, Virus, Neutralization

Journal: Microbiology Spectrum

Article Title: The Comparability of Anti-Spike SARS-CoV-2 Antibody Tests is Time-Dependent: a Prospective Observational Study

doi: 10.1128/spectrum.01402-21

Figure Lengend Snippet: Linear regression lines (±95% confidence intervals) for c-pass surrogate virus neutralization test (sVNT) results and logarithmic binding assay results (top, Abbott; bottom, Roche). The dotted vertical line represents the sVNT threshold for positivity (30% inhibition). According to the manufacturers, Roche results ≥15 BAU/mL correlate with a positive neutralization test, Abbott results ≥149,1 BAU/mL correspond to a neutralization titer of at least 1:80 as indicated by horizontal dotted lines. 3 wk, 3 weeks; BAU/mL, binding antibody units per milliliter.

Article Snippet: Binding reactivities (Roche, Abbott) were compared to a well-described CE-IVD marked surrogate virus neutralization test (GenScript cPass sVNT) ( , ).

Techniques: Virus, Neutralization, Binding Assay, Inhibition

Journal: Microbiology Spectrum

Article Title: The Comparability of Anti-Spike SARS-CoV-2 Antibody Tests is Time-Dependent: a Prospective Observational Study

doi: 10.1128/spectrum.01402-21

Figure Lengend Snippet: Spearman’s ρ of rank correlations between Nil-corrected interferon γ (IFN-γ) levels after incubation with Quantiferon SARS-CoV-2 antigen mixtures 1 (Ag1-Nil) or 2 (Ag2-Nil) and antibody levels ^a

Article Snippet: Binding reactivities (Roche, Abbott) were compared to a well-described CE-IVD marked surrogate virus neutralization test (GenScript cPass sVNT) ( , ).

Techniques: Incubation

Journal: International Journal of Molecular Sciences

Article Title: Validation of a SARS-CoV-2 Surrogate Neutralization Test Detecting Neutralizing Antibodies against the Major Variants of Concern

doi: 10.3390/ijms241914965

Figure Lengend Snippet: Comparison of WT-sVNT, Icosagen, and Genscript to whole-virus neutralization test with the WT strain. Sorting of clinical samples in regard to their NT50 results (in red) and their neutralizing activity assessed by WT-sVNT (in black, ( A )), Icosagen (in purple, ( B )), and Genscript cPass (in blue, ( C )). Correlation analysis between Icosagen Relative OD and NT50 ( D ) and Genscript %Inhibition and NT50 ( E ). Spearman correlation coefficient (r) and p -value are indicated ( D , E ). ROC curve analysis of Icosagen ( F ) and Genscript cPass ( G ). AUC for each curve is indicated ( F , G ). Stratification of Icosagen results (relative OD, left Y-axis), Genscript and WT-sVNT assessments (%Inhibition and %Neutralization, respectively) on the right axis in regard to NT50 titers grouped into NT50neg (samples with NT50 below 40), NT50intermed (samples with NT50 between 40 and 250), and NT50high (samples with NT50 above 250) ( H ). Comparison of Icosagen, WT-sVNT, and Genscript assessments in clinical cohort ( I ) and in double-vaccinated cohort ( J ). The color code (sVNT = black; Icosagen = purple; Genscript = blue) is maintained throughout the text. Open squares with the corresponding color code indicate data collected from double-vaccinated cohort ( J ). The cut-offs indicated by a dotted line were set at 30% for Genscript and sVNT and 0.75 relative OD for Icosagen ( A – E , H – J ). Gray area indicates low–no neutralization detected samples below the cut-offs for all surrogate tests ( H – J ).

Article Snippet: In addition, the sVNT performed comparably to two CE-IVD-approved commercial kits, namely the Icosagen SARS-CoV-2 Neutralizing Antibody ELISA kit and the Genscript cPass kit, for the B.1 parental strain and Omicron BA.2.

Techniques: Comparison, Virus, Neutralization, Activity Assay, Inhibition

Journal: International Journal of Molecular Sciences

Article Title: Validation of a SARS-CoV-2 Surrogate Neutralization Test Detecting Neutralizing Antibodies against the Major Variants of Concern

doi: 10.3390/ijms241914965

Figure Lengend Snippet: Evaluation of Omicron BA.2-specific surrogate tests. Performance of BA.2-sVNT ( A ) and Genscript cPass supplemented with BA.2 RBD ( B ) in double-vaccinated individuals (vaccinated cohort) in comparison to VNT reported in NT50. Sorting of vaccinated samples in regard to their NT50 results (in red on the left Y-axis) and their neutralizing activity assessed by BA.2-sVNT (in black, ( A )) and Genscript-BA.2 (in blue, ( B )) on the right Y-axis. Stratification of BA.2-sVNT and Genscript BA.2 results (%Neutralization and %Inhibition, respectively) in regard to NT50 titers grouped into NT50neg (samples with NT50 below 40), NT50intermed (samples with NT50 between 40 and 250), and NT50high (samples with NT50 above 250). A Kruskal–Wallis test followed by a Dunn’s multiple comparison post hoc test was used for comparisons between three groups ( C ). The BA.2-sVNT results are in black, and the Genscript-BA.2 results are in blue p -values < 0.05 were considered significant. **: p < 0.01; ***: p < 0.001. ****: p < 0.0001.

Article Snippet: In addition, the sVNT performed comparably to two CE-IVD-approved commercial kits, namely the Icosagen SARS-CoV-2 Neutralizing Antibody ELISA kit and the Genscript cPass kit, for the B.1 parental strain and Omicron BA.2.

Techniques: Comparison, Activity Assay, Neutralization, Inhibition