Journal: Vaccine

Article Title: Humoral immune response characterization of heterologous prime-boost vaccination with CoronaVac and BNT162b2

doi: 10.1016/j.vaccine.2022.07.023

Figure Lengend Snippet: Fc-mediated functions and RBD-ACE2 binding inhibition of specific serum anti-RBD immunoglobulins . Figure shows ADCC (A) and ADCP (B) Fc-mediated functions of serum anti-RBD immunoglobulin in 20 individuals early after two doses of Coronavac (t 1 ) and after heterologous booster with BNT162b2 (t 3 ). Endpoint titers were calculated by interpolating the reciprocal of serum dilutions to baseline, whose values were determined for each plate as the mean signal in absence of serum plus three standard deviations. Inhibition of RBD-ACE2 binding (C) and serum anti-RBD IgG levels (D) were measured in the same samples, showing a similar behavior over time. Comparison of the RBD-ACE2 binding inhibition activity against SARS-CoV-2 Wuhan and Omicron variants were carried out by sVNT in these 20 samples (E). Numbers represents median values and the interquartile range (in parentheses). Comparisons between groups were carried out using Wilcoxon test. *p < 0.05, ** p = 0.01–0.001, *** p < 0.001. BAU, binding antibody units; AU, arbitrary units.

Article Snippet: The blockade of RBD-ACE2 interaction by specific anti-SARS-CoV-2 antibodies was analyzed by using an in vitro surrogate virus neutralization test (sVNT; cPassTM SARS-CoV-2 Neutralization Antibody Detection Kit, GenScript®) in serum from individuals who received heterologous vaccination at t 1 and t 2 (post-2D with CoronaVac) and at t 3 and t 4 (post-3D with BNT162b2), according to manufacturer’s instructions.

Techniques: Binding Assay, Inhibition, Comparison, Activity Assay

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: medRxiv

Article Title: Long-term immunogenicity of BNT162b2 vaccination in the elderly and in younger health care workers

doi: 10.1101/2021.08.26.21262468

Figure Lengend Snippet: (A) Anti-S1 IgG in serum measured by a microarray-based immunoassay, (B) serum pseudovirus neutralization against the Delta VOC two and six months after vaccination measured by pNT, and (C) SARS-CoV-2 S1 specific T cell response detected by IGRA. Dotted horizontal lines indicate themanufacturer’s threshold for anti-S1 IgG ≥1 S/Co (A) and the lower limit of detection (1:10 dilution) for pNT (B). Horizontal lines within plotted data regions indicate the median and interquartile range, except for pNT, where the geometric mean and 95% confidence interval is shown. P values (all <0.0001) were calculated by non-parametric Mann Whitney U test. S/Co: signal-to-cutoff, pNT: pseudovirus neutralization test, ID 50 : 50% inhibition dilution, IGRA: interferon-γ release assay, IU: international units.

Article Snippet: Functional neutralization capacity was investigated using a commercially available ELISA-based SARS-CoV-2 RBD-ACE2 binding inhibition assay (surrogate SARS-CoV-2 neutralization test (sVNT) cPass (medac GmbH, https://international.medac.de ).

Techniques: Microarray, Neutralization, MANN-WHITNEY, Inhibition, Release Assay

Journal: medRxiv

Article Title: Long-term immunogenicity of BNT162b2 vaccination in the elderly and in younger health care workers

doi: 10.1101/2021.08.26.21262468

Figure Lengend Snippet: ( A ) Anti-SARS-CoV-2 N, ( B ) RBD- ( C ) and full-spike IgG measured in the serum of BNT162b2 vaccinated HCW and elderly persons six months after the first vaccination. ( D ) Neutralizing capacity was measured by sVNT and ( E ) serum neutralization against Alpha (B.1.1.7) VOC detected by pNT in vaccinated HCW and elderly persons six months after the first vaccination. ( F ) Binding capacity of serum IgG against six different RBDs of SARS-CoV-2 variants carrying the indicated mutations in HCW and elderly, measured by ELISA. Dotted lines indicate the manufacturer’s threshold values: for anti-N, anti-RBD, and anti-full spike IgG ≥1 S/Co, for sVNT >30%, and the lower limit of detection (1:10 dilution) for pNT. Lines indicate the median and interquartile range except for pNT, where the geometric mean and 95% confidence interval are shown. P values were calculated by the non-parametric Mann Whitney U test or Kruskal-Wallis test with Dunn’s multiple comparisons test. S/Co: signal-to-cutoff, N: nucleocapsid protein, RBD: receptor-binding domain, sVNT: surrogate virus neutralization test, ACE2: angiotensin-converting enzyme 2, ID50: 50% inhibition dilution.

Article Snippet: Functional neutralization capacity was investigated using a commercially available ELISA-based SARS-CoV-2 RBD-ACE2 binding inhibition assay (surrogate SARS-CoV-2 neutralization test (sVNT) cPass (medac GmbH, https://international.medac.de ).

Techniques: Neutralization, Binding Assay, Enzyme-linked Immunosorbent Assay, MANN-WHITNEY, Inhibition

Journal: Viruses

Article Title: Characterization of a Broadly Neutralizing Monoclonal Antibody against SARS-CoV-2 Variants

doi: 10.3390/v14020230

Figure Lengend Snippet: Analysis of mAb 9G8 blocking the SARS-CoV-2 spike RBD variant from binding to the human ACE2 receptor by surrogate virus neutralization test (sVNT). The percent inhibition of mAb 9G8 was measured against RBD of SARS-CoV-2 WT or SARS-CoV-2 variants such as Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Kappa (B.1.617.1), Delta (B.1.617.2), Delta Plus/AY.1 (B.1.617.2.1), and Epsilon (B.1.429/7). The mAb 6C8 specific for nucleocapsid protein was used as a negative control. The results were expressed as the arithmetic mean of percent-blocking values of triplicates and ±SD of the mean.

Article Snippet: To determine the neutralizing activity of mAbs against SARS-CoV-2 variants, a GenScript cPASS surrogate virus neutralization test (sVNT) was performed according to manufacturer’s instructions (GenScript, Piscataway, NJ, USA).

Techniques: Blocking Assay, Variant Assay, Binding Assay, Virus, Neutralization, Inhibition, Negative Control