<p>The normalized values (A) and avidity index (B), as measured by the Bio-Plex assay, for longitudinal seroconverters were plotted over days since seroconversion. Gray diamonds indicate individual data points and solid black circles represent the curve fit for each graph. Dashed red lines represent the half maximal response of the curve and lower 99.9% confidence limits of the estimate, while the solid black line represents the selected cutoff.</p
