FIG 3.

A subject with extremely high anamnestic DENV1 NAbs attributed mainly to IgA. (A) Neutralization curves with and without IgG depletion for plasma samples from individual 19 with higher NAb to DENV1 than to ZIKV at each time point. Dotted lines represent 90% neutralization. (B) Comparison of PRNT₉₀ titers using DENV1 16007 and West Pac74 for 4 samples from the subject. No significant difference in NAb titers was measured by a two-tailed paired t test, indicating that the higher DENV1 titer was not attributable to the use of the DENV1 16007 strain in R-WN/DENV1. (C) NAb was tested in the R-mFRNT with DENV1 and ZIKV after IgG depletion, IgG/M depletion, and IgG/A depletion of plasma samples from the same individual. Asterisks indicate significant differences by ANOVA with Tukey’s multiple-comparison test (*, P < 0.05; **, P < 0.001; ***, P < 0.0001).