Fig. 2: Humoral and cell-mediated immune responses in mice.
From: A single-dose live-attenuated YF17D-vectored SARS-CoV-2 vaccine candidate
Ifnar−/− mice were vaccinated twice (at day 0 and day 7) intraperitoneally with 400 PFU of each construct. a, b, NAbs (a) and binding antibodies (b) on day 21 after vaccination. c, Seroconversion rates at the indicated days. d, Ratios of IgG2b or IgG2c to IgG1, compared to a theoretical TH1 or TH2 cell response. In a–d, mice were vaccinated with YF-S1/2 (n = 11), YF-S0 (n = 11), YF-S1 (n = 13), sham (n = 9) or YF17D (n = 9); data from 3 independent experiments. For binding antibody quantification (b) and IgG subtyping (d), serum minipools from two or three mice were used. e, Number of IFNγ-secreting cells after SARS-CoV-2 S-peptide pool stimulation. Mice were vaccinated with YF-S1/2 (n = 11), YF-S0 (n = 10), YF-S1 (n = 7), sham (n = 9) or YF17D (n = 5). YF-S1 and YF17D from two, and YF-S1/2, YF-S0 and sham from three, independent experiments. f, Normalized mRNA expression levels of Tbx21, Gata3, Rorc and Foxp3 quantified by RT–qPCR in S-peptide-stimulated splenocytes. Data are expressed as fold change over median of uninfected controls (n = 5 YF-S1/2, YF-S0 and YF-S1, n = 7 sham and n = 3 uninfected controls from a single experiment). g, Percentage of IFNγ- and TNF-expressing CD8 cells, and IFNγ-expressing CD4 and γδ T cells, after S peptide stimulation. Mice were vaccinated with YF-S1/2 (n = 11), YF-S0 (n = 10), YF-S1 (n = 5), YF17D (n = 5) or sham (n = 8); YF-S1 and YF17D from a single experiment; YF-S1/2, YF-S0 and sham from three independent experiments. h, i, t-SNE of S-specific CD8 T cells positive for at least one intracellular marker (IFNγ, TNF or IL-4) after S-peptide stimulation (n = 6 for YF-S1/2 and YF-S0). i, Heat map of IFNγ expression density of S-specific CD8 T cells after YF-S1/2 and YF-S0 vaccination. Scale bar represents density of IFNγ-expressing cells; blue, low expression; red, high expression. Data in b–k are median ± IQR. Two-tailed uncorrected Kruskal–Wallis test (b, c, f–k) or a one-sample t-test (e) was applied.
