Journal: Frontiers in Immunology

Article Title: Humoral Immune Response Diversity to Different COVID-19 Vaccines: Implications for the “Green Pass” Policy

doi: 10.3389/fimmu.2022.833085

Figure Lengend Snippet: Spearman’s correlation analysis of serum anti-receptor-binding domain (anti-RBD) antibody titers and neutralizing activity in 70 participants in the study (22 vaccinated with BNT162b2, 9 with mRNA-1273, 27 with ChAdOx1 nCov19, 9 with Ad26.COV2.S, 1 COVID-19 convalescent, and 2 with mixed vaccines). (A) Correlation plot of anti-RBD antibody titers versus neutralizing activity (percentage inhibition of RBD-ACE2 binding) assessed through the cPass™ ELISA-based assay. (B) Correlation plot of anti-RBD antibody titers versus neutralizing activity assessed through IgG/Neutralizing Antibody Rapid Test. (C) Correlation plot of neutralizing activity evaluated through cPass™ ELISA-based assay and IgG/Neutralizing Antibody Rapid Test cassettes. Trendlines, Spearman’s r , and p -values are also represented (statistical significance for p < 0.05).

Article Snippet: Some of them have high costs, require trained personnel, and can only be carried out in a Biosafety Safety Level 3-equipped laboratory, whereas others, such as the cPass surrogate virus neutralization test (sVNT) (GenScript, Piscataway, NJ, USA) used in this work, are ELISA-based assays and only require optical density readers.

Techniques: Binding Assay, Activity Assay, Vaccines, Inhibition, Enzyme-linked Immunosorbent Assay

Journal: Frontiers in Immunology

Article Title: Humoral Immune Response Diversity to Different COVID-19 Vaccines: Implications for the “Green Pass” Policy

doi: 10.3389/fimmu.2022.833085

Figure Lengend Snippet: Neutralizing activity evaluated by cPass™ ELISA-based SARS-CoV-2 Neutralization Antibody Detection Kit in 70 sera from differently vaccinated individuals. Serum samples were considered positive when ≥30% inhibition was measured, as shown by the red line in the graph. (A) Percentage inhibition of receptor-binding domain–angiotensin-converting enzyme 2 (RBD-ACE2) binding within different vaccination groups (see also Table 3 ). Statistical significance was assessed by ANOVA following Tukey’s multiple comparisons test, ** p < 0.005, * p < 0.05. (B) Comparison of neutralizing activity in sera from individuals who received adenoviral DNA-based vaccines and mRNA-based vaccines. Statistical significance was assessed by unpaired t-test, * p = 0.0016.

Article Snippet: Some of them have high costs, require trained personnel, and can only be carried out in a Biosafety Safety Level 3-equipped laboratory, whereas others, such as the cPass surrogate virus neutralization test (sVNT) (GenScript, Piscataway, NJ, USA) used in this work, are ELISA-based assays and only require optical density readers.

Techniques: Activity Assay, Enzyme-linked Immunosorbent Assay, Neutralization, Inhibition, Binding Assay, Comparison, Vaccines

Journal: Frontiers in Immunology

Article Title: Humoral Immune Response Diversity to Different COVID-19 Vaccines: Implications for the “Green Pass” Policy

doi: 10.3389/fimmu.2022.833085

Figure Lengend Snippet: Mean neutralizing activity measured by the cPass™ ELISA-based assay in sera from 70 individuals who received different vaccines.

Article Snippet: Some of them have high costs, require trained personnel, and can only be carried out in a Biosafety Safety Level 3-equipped laboratory, whereas others, such as the cPass surrogate virus neutralization test (sVNT) (GenScript, Piscataway, NJ, USA) used in this work, are ELISA-based assays and only require optical density readers.

Techniques: Activity Assay, Enzyme-linked Immunosorbent Assay, Vaccines

Journal: Scientific Reports

Article Title: Evaluation of commercially available fully automated and ELISA-based assays for detecting anti-SARS-CoV-2 neutralizing antibodies

doi: 10.1038/s41598-022-21317-x

Figure Lengend Snippet: Analytical performance of the evaluated sVNT assays using the pre-defined cutoff values and the newly calculated cutoff values determined using Youden's index.

Article Snippet: Further, GenScript cPass sVNT exhibited the best linear correlation with pVNT in samples collected from both infected and vaccinated individuals.

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 of each kit in discriminating SARS-CoV-2 infection.

Article Snippet: For the GenScript cPass sVNT kit, dilution was not conducted because the method represents the result of the inhibition ratio calculated from the optical density measured, which does not necessarily linearly correlate with the titer of the antibodies.

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: For the GenScript cPass sVNT kit, dilution was not conducted because the method represents the result of the inhibition ratio calculated from the optical density measured, which does not necessarily linearly correlate with the titer of the antibodies.

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: For the GenScript cPass sVNT kit, dilution was not conducted because the method represents the result of the inhibition ratio calculated from the optical density measured, which does not necessarily linearly correlate with the titer of the antibodies.

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: For the GenScript cPass sVNT kit, dilution was not conducted because the method represents the result of the inhibition ratio calculated from the optical density measured, which does not necessarily linearly correlate with the titer of the antibodies.

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: For the GenScript cPass sVNT kit, dilution was not conducted because the method represents the result of the inhibition ratio calculated from the optical density measured, which does not necessarily linearly correlate with the titer of the antibodies.

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: For the GenScript cPass sVNT kit, dilution was not conducted because the method represents the result of the inhibition ratio calculated from the optical density measured, which does not necessarily linearly correlate with the titer of the antibodies.

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