Figure 1.

(A) Determination of avidity index by ELISA using a multiple diluted serum exposed a single concentration of chaotropic agents. The arrow of the dashed line in the x‐axis shows dilution of serum exposed to a chaotropic agent accordant to the certain cutoff absorbance; the arrow of the solid line in the x‐axis shows dilution of serum without chaotrope exposition accordant to the certain cutoff absorbance. (B) Determination of avidity index based on the ratio of areas derived from the antibody titration curve. The solid line borders the area without chaotrope and the dashed line borders the area with chaotrope