Th2 type response by age group, in years: Panel A: Percent of H. pylori seropositive individuals with Th2-dominant IgG H. pylori specific immune response by age group. Panel B: Log-transformed IgG1/IgG2 ratio by age group among H. pylori seropositive individuals in rural Tanzania. The X-axis shows age groups in years, the Y-axis shows log-transformed values. The y-line marks the cut-off value for T helper (Th)-dominant 1 vs. Th2-dominant response: values above the line indicate Th2-dominant responses, while values below the line indicate Th1-dominant responses. The line plot connects the median log-transformed IgG1/2 ratios for each age group and the scattered points indicate actual values for each age group.