Fig. 3: Dynamic change of neutralizing antibody response in COVID-19 convalescents.
a,b, Kinetics of anti-RBD IgG and MN titres against SARS-CoV-2 during the 480 d follow-up. The black solid line represents the fitted curve obtained using the LOESS curve-fitting polynomial regression. Grey band areas represent 95% confidence intervals. c,d, Donor-matched peak and current anti-RBD IgG/MN titres. Only individuals in whom the peak anti-RBD IgG (N = 46) and MN titres (N = 48) occurred before the last timepoint (≥270 d.a.o.) are included in this analysis, and each line represents one individual. Individuals in severe, mild and asymptomatic groups are marked in red, blue and purple, respectively. Statistical significance was determined using a two-sided Mann–Whitney U-test. Dotted lines indicate the limit of detection. e, The ratio of current/peak anti-RBD IgG and MN titres for the three groups. The line and error bar represent the mean and standard deviation. f, Proportion of the different decrease rates in MN titres for the three groups. Specimens with MN titres <10 were assigned a value of 5, and MN titres ≥320 were assigned a value of 320.
