Fig. 4
Kinetics of anti-Spike antibodies in NPS. Swabs collected at the hospital admission and during hospitalization were assayed by ELISA. (a) Kinetics of total IgG and IgA and anti-Spike (S) IgG and IgA (mean ± SEM). Data are expressed as ng/ml. (b) Kinetics of the percentage of anti-Spike IgG and IgA. Asterisks indicate a significant difference between IgG and IgA (*p < 0,05, **p < 0,01, ***p < 0,001, Wilcoxon matched-pairs signed rank test). (c) Evaluation of neutralizing activity in NPS. Selected patients (N = 19) with serum nAbs (ID50 > 100) were assayed for anti-Wuhan nAbs in NPS. The corresponding value in serum is also indicated. Each dot represents a single patient. Results are expressed as ID50. The dotted line indicates the assay cut off (minimum sample dilution tested: 1:10 dilution).
