Fig. 2.

Background-subtracted readouts from the QFT-GIT. Assay magnitudes (IFN-γ ELISA readout) are plotted on a log-scale, by treatment group and visit. Each participant is represented as a single line with one symbol per visit/sample. A dashed line indicates the manufacturer's recommended positivity threshold (≥0.35 IU/mL). The shaded gray area indicates the “uncertainty” area as defined in (12) in which they showed changes in response magnitude from below the shaded region (<0.2 IU/mL) to a level above the region (>0·7 IU/mL) were more strongly associated with increased risk of TB disease. The post-vaccine responses among participants in the H56:IC31 group may indicate vaccine-induced responses as H56 contains one of the antigens in the QFT-GIT assay.