Fig. 3

Neutralisation activity against the original variant in recovered mild/moderate COVID-19 patients with various levels of anti-Spike and RBD IgG antibodies. Magnitude of neutralisation activity against the original variant (D614G) in first wave sera with varying concentrations of A anti-Spike IgG and B anti-RBD IgG antibodies. The Spike and RBD protein antigens were from the original D614G variant. Vertical bars represent geometric mean and horizontal bars represent 95% confidence intervals. Data was log 10 transformed and statistics were calculated using ordinary one-way ANOVA and p value adjusted for multiple comparison using Šídák’s multiple comparisons test (n = 30). A p < 0.05 was regarded as statistically significant. S, full-length Spike; RBD, receptor-binding domain; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2