Journal: Frontiers in Cellular and Infection Microbiology

Article Title: Estimating the Neutralizing Effect and Titer Correlation of Semi-Quantitative Anti-SARS-CoV-2 Antibody Immunoassays

doi: 10.3389/fcimb.2022.822599

Figure Lengend Snippet: Analytical performance of each kit in discriminating SARS-CoV-2 infection.

Article Snippet: ND 50 ≥ 20 , cPass sVNT , GenScript, RBD, total , 94.68% (91.51%–96.93%) , 81.32% (74.89%–86.70%) , 0.78.

Techniques: Infection

Journal: Frontiers in Cellular and Infection Microbiology

Article Title: Estimating the Neutralizing Effect and Titer Correlation of Semi-Quantitative Anti-SARS-CoV-2 Antibody Immunoassays

doi: 10.3389/fcimb.2022.822599

Figure Lengend Snippet: Analytical performance for representativeness of neutralizing activity using the pre-defined cut-off values of each immunoassay kit.

Article Snippet: ND 50 ≥ 20 , cPass sVNT , GenScript, RBD, total , 94.68% (91.51%–96.93%) , 81.32% (74.89%–86.70%) , 0.78.

Techniques: Activity Assay

Journal: Frontiers in Cellular and Infection Microbiology

Article Title: Estimating the Neutralizing Effect and Titer Correlation of Semi-Quantitative Anti-SARS-CoV-2 Antibody Immunoassays

doi: 10.3389/fcimb.2022.822599

Figure Lengend Snippet: Titer correlation of the analytical performance of the prediction of neutralizing activity using newly calculated cut-off values determined using Youden’s index.

Article Snippet: ND 50 ≥ 20 , cPass sVNT , GenScript, RBD, total , 94.68% (91.51%–96.93%) , 81.32% (74.89%–86.70%) , 0.78.

Techniques: Activity Assay

Journal: Frontiers in Cellular and Infection Microbiology

Article Title: Estimating the Neutralizing Effect and Titer Correlation of Semi-Quantitative Anti-SARS-CoV-2 Antibody Immunoassays

doi: 10.3389/fcimb.2022.822599

Figure Lengend Snippet: Serial kinetics of antibody titers measured with each method: (A) PRNT ND50, (B.) GenScript cPass sVNT, (C) Roche Elecsys Anti-SARS-CoV-2, (D) Roche Elecsys Anti-SARS-CoV2 S, and (E) Abbott AdviseDx SARS-CoV2 IgG II.

Article Snippet: ND 50 ≥ 20 , cPass sVNT , GenScript, RBD, total , 94.68% (91.51%–96.93%) , 81.32% (74.89%–86.70%) , 0.78.

Techniques:

Journal: Frontiers in Cellular and Infection Microbiology

Article Title: Estimating the Neutralizing Effect and Titer Correlation of Semi-Quantitative Anti-SARS-CoV-2 Antibody Immunoassays

doi: 10.3389/fcimb.2022.822599

Figure Lengend Snippet: Antibody titers by timeline.

Article Snippet: ND 50 ≥ 20 , cPass sVNT , GenScript, RBD, total , 94.68% (91.51%–96.93%) , 81.32% (74.89%–86.70%) , 0.78.

Techniques:

Journal: Frontiers in Cellular and Infection Microbiology

Article Title: Estimating the Neutralizing Effect and Titer Correlation of Semi-Quantitative Anti-SARS-CoV-2 Antibody Immunoassays

doi: 10.3389/fcimb.2022.822599

Figure Lengend Snippet: Scatter plot and Pearson’s correlation for each method grouped with acute/convalescent phase. (A) GenScript cPass sVNT, (B) Roche Elecsys Anti-SARS-CoV-2, (C) Roche Elecsys Anti-SARS-CoV2 S, and (D) Abbott AdviseDx SARS-CoV2 IgG II were compared with PRNT, respectively. Each colored line depicts the linear regression model and the surrounding grey-colored area represents the 95% confidence interval.

Article Snippet: ND 50 ≥ 20 , cPass sVNT , GenScript, RBD, total , 94.68% (91.51%–96.93%) , 81.32% (74.89%–86.70%) , 0.78.

Techniques:

Journal: medRxiv

Article Title: Function is more reliable than quantity to follow up the humoral response to the Receptor Binding Domain of SARS- CoV-2 Spike protein after natural infection or COVID-19 vaccination

doi: 10.1101/2021.06.02.21257975

Figure Lengend Snippet: Panel A shows the mean time of sample collection following natural infection (n=25) or after the first vaccine dose (n=20). In panel B and C, results from the total anti-Spike protein and the IgG titer measured by Enzyme-linked immunosorbent assay and expressed as OD or titers respectively are presented. The threshold for the total antibodies was 0.312 and the threshold for IgG titers was 1:100. All participants, except one, with previous exposure to SARS-CoV-2 showed detectable antibodies and measurable titers at baseline. Because the threshold 1:100 of our titration assay, the IgG titers at baseline in the unexposed subjects—which had no detectable S-specific antibodies—were set arbitrarily to 50. Panel D shows the blocking activity of serum antibodies expressed as percentage of neutralization by using a surrogate viral neutralization test (sVNT). The cutoff for this assay was 30%. As is shown, only one sample in the pre-exposed group contained antibodies below the threshold reported as more than 30% of neutralization. Also, while the distribution of antibodies and titers covers the full Y axis, values in both panel B and C, and in panel D same samples are grouped on the top values area. Two-way ANOVA multiple comparisons or unpaired T test analysis was used to test for increases or decreases among samples. P<0.05 was considered significant. Twenty-five participants (Natural infected) out of the 59 with the first sample collected between 12 and 39 days after the confirmed infection with SARS-CoV-2 were selected for comparison with the 21 unexposed-vaccinated subgroup (Healthy-vaccinated).

Article Snippet: To determine the neutralizing activity of antibodies we used a surrogate viral neutralization test (C-Pass GenScript sVNT, Piscataway NJ) ( , ).

Techniques: Infection, Enzyme-linked Immunosorbent Assay, Titration, Blocking Assay, Activity Assay, Neutralization, Comparison

Journal: medRxiv

Article Title: Function is more reliable than quantity to follow up the humoral response to the Receptor Binding Domain of SARS- CoV-2 Spike protein after natural infection or COVID-19 vaccination

doi: 10.1101/2021.06.02.21257975

Figure Lengend Snippet: Samples are described as 1st or 2nd samples after 1 st or 2 nd vaccine dose (1S-P1st-vd, 1S-P2nd-vd or 2S-P2nd-vd) and the mean time of samples collection is shown. Panels A and B show the total antibody and IgG titers, respectively, after full vaccination with two vaccine doses. Antibody levels and titers significantly decay in both groups in a second sample collected after the second vaccine (average of 60.3 and 100.5 days after the first vaccine dose for the unexposed and pre-exposed groups respectively). Despite the difference in sampling time between the two groups, there were no significant differences in the levels of antibodies or titers between groups in the 2S-P2nd-vd. Panel C shows antibody blocking capabilities measured by a surrogate viral neutralization assay (sVNT). Highly relevant is the finding that the blocking baseline activity of the pre-exposed individuals is significantly higher than the basely blocking activity induced by the first vaccine dose in unexposed individuals. In addition, two vaccine doses were necessary in the unexposed cohort to induce same percentage of neutralization achieved by just the first dose in the pre-exposed group. The magnitude of neutralization remained at similar levels until the last time point evaluated in both groups, confirming that the surrogate neutralization test is more suitable to determine the efficacy of the humoral immune response to the vaccine. The threshold for the total antibodies was 0.312. The threshold for IgG titers was 1:100 and for the blocking activity was 30%. Statistical significance was determined by two-way ANOVA multiple comparisons to test for increase or decrease among samples. p<0.05 was considered significant. The black arrows indicate the moment of vaccine administration related to the timing of sample collection. Healthy-vaccinated (n=21) Pre-exposed vaccinated (n=10).

Article Snippet: To determine the neutralizing activity of antibodies we used a surrogate viral neutralization test (C-Pass GenScript sVNT, Piscataway NJ) ( , ).

Techniques: Sampling, Blocking Assay, Neutralization, Activity Assay

Journal: Diagnostics

Article Title: Performance of a Point-of-Care Fluorescence Immunoassay Test to Measure the Anti-Severe Acute Respiratory Syndrome Corona Virus 2 Spike, Receptor Binding Domain Antibody Level

doi: 10.3390/diagnostics13243686

Figure Lengend Snippet: Advantages and disadvantages of FastBio-RBD TM (fluorescence immunoassay) and GenScript-cPASS TM (SVNT).

Article Snippet: The correlation analysis showed that FastBio-RBD showed a very strong positive correlation to the Genscript SVNT, comparable with more sophisticated tests like the ECLIA and ELISA-based tests [ ].

Techniques: Fluorescence, Clinical Proteomics, Inhibition, Binding Assay, Neutralization, Comparison, Enzyme-linked Immunosorbent Assay

Journal: PLoS ONE

Article Title: Early detection of neutralizing antibodies against SARS-CoV-2 in COVID-19 patients in Thailand

doi: 10.1371/journal.pone.0246864

Figure Lengend Snippet: The serology test results of 0–7, 8–14, 15–21, 22–28 days after symptom onset were compared (lateral axis), respectively. Each dot represents one tested specimen and the vertical axis represents the %inhibition of SARS-CoV-2 NAbs tested by sVNT. The dash line represents the cutoff at 20% inhibition. The horizontal lines indicates the median interquartile range (IQR). The p values were calculated from two-tailed test.

Article Snippet: Blood specimens from patients with PCR-confirmed COVID-19 were tested for NAbs against SARS-CoV-2 antibodies using sVNT assay (cPassTM, GenScript USA), according to the manufacturer’s instructions.

Techniques: Inhibition, Two Tailed Test

Journal: PLoS ONE

Article Title: Early detection of neutralizing antibodies against SARS-CoV-2 in COVID-19 patients in Thailand

doi: 10.1371/journal.pone.0246864

Figure Lengend Snippet: Every dot represents one tested specimen and the vertical axis represents the %inhibition of SARS-CoV-2 NAbs tested by sVNT. The dashed line represents the cutoff at 20% inhibition. The horizontal lines indicate the median interquartile range (IQR). The p values were calculated from two-tailed test.

Article Snippet: Blood specimens from patients with PCR-confirmed COVID-19 were tested for NAbs against SARS-CoV-2 antibodies using sVNT assay (cPassTM, GenScript USA), according to the manufacturer’s instructions.

Techniques: Inhibition, Two Tailed Test

Journal: PLoS ONE

Article Title: Early detection of neutralizing antibodies against SARS-CoV-2 in COVID-19 patients in Thailand

doi: 10.1371/journal.pone.0246864

Figure Lengend Snippet: Every dot represents one tested specimen and the vertical axis represents the %inhibition of SARS-CoV-2 NAbs tested by sVNT. The dashed line represents the cutoff at 20% inhibition. The horizontal lines indicate the median interquartile range (IQR). The p values were calculated from two-tailed test.

Article Snippet: Blood specimens from patients with PCR-confirmed COVID-19 were tested for NAbs against SARS-CoV-2 antibodies using sVNT assay (cPassTM, GenScript USA), according to the manufacturer’s instructions.

Techniques: Inhibition, Two Tailed Test

Journal: Nature

Article Title: Nanobodies from camelid mice and llamas neutralize SARS-CoV-2 variants

doi: 10.1038/s41586-021-03676-z

Figure Lengend Snippet: a , Table indicating (1) the total number of unique nanobody genes identified from llama and three nanomice phage display libraries following selection for RBD binding; (2) the number of nanobodies enriched at least tenfold after selection; (3) the number of nanobodies with a unique CRD3; and (4) the different clusters of nanobodies that share similar CDR3 s (with no more than 2 amino acid differences). b , Table showing in vitro neutralization results for the six leading nanobodies using the sVNT kit of GenScript. c , Dot plot depicting the extent of enrichment ( y axis) and frequency ( x axis) of unique nanobodies after RBD selection of llama (left) or nanomouse 1 (right) libraries. Green circles represent nanobodies that block ACE2–RBD interactions in vitro, black circles are nanobodies that do not efficiently block ACE2–RBD interactions, and grey dots represent untested nanobodies. d , Top graph shows protein alignment of the six nanobodies isolated from llama and nanomice immunized with SARS-CoV-2 spike and RBD. Bottom table shows detailed information of the VHH, D and J domains of nanomouse nanobodies. e , Table depicting equilibrium ( K D ), association ( K on ) and dissociation ( K off ) constants obtained for each nanobody as a monomer (black) or trimer (red) form.

Article Snippet: Extended Data Fig. 5 Isolation of anti-SARS-CoV-2 RBD nanobodies. a , Table indicating (1) the total number of unique nanobody genes identified from llama and three nanomice phage display libraries following selection for RBD binding; (2) the number of nanobodies enriched at least tenfold after selection; (3) the number of nanobodies with a unique CRD3; and (4) the different clusters of nanobodies that share similar CDR3 s (with no more than 2 amino acid differences). b , Table showing in vitro neutralization results for the six leading nanobodies using the sVNT kit of GenScript. c , Dot plot depicting the extent of enrichment ( y axis) and frequency ( x axis) of unique nanobodies after RBD selection of llama (left) or nanomouse 1 (right) libraries.

Techniques: Selection, Binding Assay, In Vitro, Neutralization, Blocking Assay, Isolation