Fig. 4.

Effects of 382-nt deletion in SARS-CoV-2 ORF8 genome on adaptive immune responses to COVID-19. a SARS-CoV-2 specific CD4⁺ and CD8⁺ non-T follicular helper (TFH) cells were characterized with flow cytometry-based on the expression of IFN-γ, IL-2, and TNF-⍺ upon SARS-CoV-2 peptide stimulation in WT (n = 14) or Δ382 SARS-CoV-2 (n = 14) infected patients. Statistical analyses were performed with the Mann–Whitney U test (**p < 0.01). b Antibody responses in Δ382 SARS-CoV-2 infected patients. Spike protein-specific antibody response was characterized using an S-flow assay. Plasma samples of COVID-19 patients infected with either WT (n = 20) or Δ382 SARS-CoV-2 (n = 30) were screened at 1:100 dilution against cells expressing the full-length SARS-CoV-2 spike protein, with healthy donors (n = 22) screened in parallel. IgM and IgG profiles of COVID-19 patients at timepoints ≤ 7, 8 to 14, and 15 to 30 days PIO are illustrated as violin plots. The dotted line indicates the mean + 3SD of healthy donors. Data are shown as mean ± SD of two independent experiments. For determination of anti-peptide IgG responses, plasma samples o COVID-19 patients infected with either WT (n = 20) or Δ382 SARS-CoV-2 (n = 30) were tested at 1:1000 dilution on an IgG ELISA against SARS-CoV-2 spike epitopes S21P2 and S14P5. Healthy controls (n = 22) were screened in parallel. Antibody profiles of COVID-19 patients at timepoints ≤ 7, 8 to 14, 15 to 30 days PIO are illustrated as violin plots. The dotted line indicates the mean + 3SD of healthy controls. Data are shown as mean ± SD of two independent experiments. Statistical analysis was carried out using Mann–Whitney U tests (*p < 0.05). WT, wildtype