Journal: Nature Communications

Article Title: SARS-CoV-2 spike glycoprotein vaccine candidate NVX-CoV2373 immunogenicity in baboons and protection in mice

doi: 10.1038/s41467-020-20653-8

Figure Lengend Snippet: a Groups of mice ( n = 6/group) were immunized with 10 μg NVX-CoV2373 with and without 5 μg Matrix-M adjuvant in two doses spaced 21 days apart. A negative control group ( N = 3) was not immunized. Splenocytes were collected 7 days after the second immunization (study day 28) and stimulated with a peptide pool (PP) that covers the entire spike protein for 6 h. b The number of IFN-γ secreting cells per million splenocytes was determined by ELISpot ( n = 6/group). c , d The frequency of CD4 + memory T cells and CD8 + memory T cells producing IFN-γ, TNF-α, and IL-2, or at least 2 of 3 cytokines was determined by intracellular cytokine staining ( n = 6/group). Analyzed cells were gated on the CD44 hi CD62L − effector memory population. Bars represent the mean and the error bars indicate ±SD of triplicate assays. Individual animal values are indicated by colored symbols. Comparisons between groups receiving NVX-CoV2373 with and without adjuvant was performed by Student’s t -test (unpaired, two tail). e Pie charts represent the relative proportion of CD4 + and CD8 + T cells producing one, two, or three cytokines (IFN-γ, TNF-α, and IL-2) in mice immunized with NVX-CoV2373 antigen with and without Matrix-M. Source data are provided as a Source Data file.

Article Snippet: Assay plates were incubated overnight at 37 °C in a 5% CO 2 incubator and developed using BD ELISpot AEC substrate set (BD Biosciences, San Diego, CA).

Techniques: Negative Control, Enzyme-linked Immunospot, Staining

Journal: Nature Communications

Article Title: SARS-CoV-2 spike glycoprotein vaccine candidate NVX-CoV2373 immunogenicity in baboons and protection in mice

doi: 10.1038/s41467-020-20653-8

Figure Lengend Snippet: a Baboons were randomly assigned to groups ( n = 2–3/group) and immunized by IM injection with 1, 5, or 25 μg of NVX-CoV2373 and 50 μg Matrix-M adjuvant in two doses spaced 21 days apart (D0 and D21). A separate group ( n = 2) received two doses of 25 μg NVX-CoV2373 without adjuvant. For serologic analysis, serum was collected prior to immunization (D0) and 21, 28, and 35 days after the first immunization (red triangle). For cellular responses, peripheral blood mononuclear cells (PBMCs) were collected 7 days after the booster (blue triangle) and re-stimulated with purified NVX-CoV2373 spike protein. b Anti-SARS-CoV-2 S IgG titers were determined by ELISA. c hACE2-receptor-blocking antibodies were determined by ELISA. d SARS-CoV-2-neutralizing antibodies determined by in vitro inhibition of cytopathic effect (CPE). Sold bars indicate the group mean and the colored symbols are individual animal values. The horizontal dashed black line indicates the limit of detection (LOD) for each assay. e Correlation of anti-SARS-CoV-2 S IgG titers vs SARS-CoV-2-neutralizing antibodies. f IFN-γ-secreting PBMCs re-stimulated with NVX-CoV2373 protein were determined by ELISpot anaylsis. g Frequency of SARS-CoV-2 spike-specific CD4 + T cells producing single and multiple combinations of type 1 cytokines IFN-γ, TNF-α, and IL-2 determined by intracellular cytokine staining (ICCS). Solid bars represent the group mean and individual animal values are indicated by colored symbols. Source data are provided as a Source Data file.

Article Snippet: Assay plates were incubated overnight at 37 °C in a 5% CO 2 incubator and developed using BD ELISpot AEC substrate set (BD Biosciences, San Diego, CA).

Techniques: Injection, Purification, Enzyme-linked Immunosorbent Assay, Blocking Assay, In Vitro, Inhibition, Enzyme-linked Immunospot, Staining