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: Frontiers in Medicine

Article Title: SARS-CoV-2-Specific Antibody (Ab) Levels and the Kinetic of Ab Decline Determine Ab Persistence Over 1 Year

doi: 10.3389/fmed.2022.822316

Figure Lengend Snippet: (A–E) Kinetics of SARS-CoV-2-specific Abs measured with different assays. (A) NT_50 titers 1:x, (B) % inhibition in sVNT (negative cut-off 20%), (C) S1-specific IgG in BAU/ml (positive cut-off 35.2), (D) RBD-specific IgG in IU/ml, and (E) NCP-specific IgG (ratios, negative cut-off 0.8) post-infection and 3 months, 6 months and 1 year thereafter; dashed red lines indicate positive (NT_50, S1-specific IgG) and negative (sVNT, NCP-specific IgG) cut-off values; dashed gray line—proposed positive cut-off for RBD-specific IgG. BAU, binding antibody units; IU, international antibody units; NT_50, reciprocal sample dilution resulting in 50% virus neutralization; mo, months; NCP, SARS-CoV-2 nucleo capside protein; RBD, SARS-CoV-2 receptor binding domain; S1, SARS-CoV-2 Spike protein 1; sVNT, surrogate-virus neutralization test; y, year.

Article Snippet: SARS-CoV-2-NeutraLISA surrogate virus neutralization test (sVNT) obtained from Euroimmune®, Euroimmun Medizinische Labordiagnostik AG (Lübeck, Germany) was performed according to manufacturer's instructions and results were calculated as % inhibition with following interpretation: % inhibition <20—negative; % inhibition ≥20 to <35—borderline; % inhibition ≥35—positive).

Techniques: Inhibition, Infection, Binding Assay, Virus, Neutralization

Journal: Frontiers in Medicine

Article Title: SARS-CoV-2-Specific Antibody (Ab) Levels and the Kinetic of Ab Decline Determine Ab Persistence Over 1 Year

doi: 10.3389/fmed.2022.822316

Figure Lengend Snippet: (A,B) Decline kinetics for (A) NT_50 titers 1: x, % inhibition in sVNT, S1-specific IgG in BAU/ml and RBD-specific IgG in IU/ml post-infection and 3 months, 6 months and 1 year thereafter. Geometric mean titers & 95% CI of NT_50 titers, geometric means & 95% CI of S1-specific IgG, RBD-specific IgG, and % inhibition in sVNT; fast corresponds to ß 1 and slow to ß 2 in Eq. 1 (see text); and (B) S1-specific IgG in BAU/ml (geometric mean & 95% CI) in infected individuals and healthy controls vaccinated twice (4-week interval) with SARS-CoV-2 mRNA vaccine (post-infection/vaccination and after 6 months).

Article Snippet: SARS-CoV-2-NeutraLISA surrogate virus neutralization test (sVNT) obtained from Euroimmune®, Euroimmun Medizinische Labordiagnostik AG (Lübeck, Germany) was performed according to manufacturer's instructions and results were calculated as % inhibition with following interpretation: % inhibition <20—negative; % inhibition ≥20 to <35—borderline; % inhibition ≥35—positive).

Techniques: Inhibition, Infection

Journal: Frontiers in Immunology

Article Title: Vaccine-induced SARS-CoV-2 antibody response: the comparability of S1-specific binding assays depends on epitope and isotype discrimination

doi: 10.3389/fimmu.2023.1257265

Figure Lengend Snippet: Neutralizing potential over time. S1-specific antibody titers (BAU/ml) for five selected time points are plotted against percentage inhibition (IH%) measured by a surrogate virus neutralization test (sVNT; SARS-CoV-2-NeutraLISA; Euroimmun). Negative cut-off, <20 IH%; positive cut-off, ≥35 IH% (green line).

Article Snippet: Therefore, we analyzed the serum level of neutralizing anti-SARS-CoV-2 antibodies in each sample using a surrogate virus neutralization test (sVNT; SARS-CoV-2 NeutraLISA; Euroimmun).

Techniques: Inhibition, Virus, Neutralization

Journal: Frontiers in Immunology

Article Title: Vaccine-induced SARS-CoV-2 antibody response: the comparability of S1-specific binding assays depends on epitope and isotype discrimination

doi: 10.3389/fimmu.2023.1257265

Figure Lengend Snippet: (A) Proportion of samples (%) in six different sVNT categories (<20; 20–45; ≥35, 35–59; 60–89; and ≥90 IH%) and above three potential BAU/ml thresholds (≥100; ≥200; and ≥400 BAU/ml) for five selected time points. (B) Proportion of samples (%) in four different categories (<35 IH%/<100 BAU/ml; <35 IH%/≥100 BAU/ml; ≥35 IH%/<100 BAU/ml; ≥35 IH%/≥100 BAU/ml) for three selected time points (TP3, TP5, and TP9).

Article Snippet: Therefore, we analyzed the serum level of neutralizing anti-SARS-CoV-2 antibodies in each sample using a surrogate virus neutralization test (sVNT; SARS-CoV-2 NeutraLISA; Euroimmun).

Techniques: