Fig. 4
sVNT positively correlates with pVNT and anti-SARS-CoV-2 S1 IgG and IgA antibodies. Correlation between sVNT1:20 and antibody titers resulting in 90% (A) or 50% (B) reduction of luciferase production in pVNT90 and pVNT50. The horizontal shaded area indicates the mean ± 2SD range of inhibition of sera from HC. Correlation between log-transformed sVNT titers (determined as in Fig. 2H) and log-transformed pVNT90 (C) and pVNT50 (D). To alleviate overplotting, the titer values were jittered by the addition of random values in the interval [−0.5, 0.5]. Correlation between sVNT1:20 and log-transformed SARS-CoV-2 S1-specific IgG (E) and IgA (F) levels measured by ELISA. The vertical shaded areas indicate the respective cutoff values recommended by the manufacturer to determine positive (right to), borderline (within) and negative (left to) shaded areas. The horizontal shaded area indicates the mean ± 2SD range of inhibition of sera from healthy controls. A–F Dots, samples of HC (black), mildly (blue), or severely (red) affected COVID-19 convalescent cases. C–F Linear correlation (solid line) and 95% confidence intervals (dotted lines). Correlation, one-way ANOVA followed by a test for the trend (A, B) or Pearson r (C–F)
