Figure 6. Duration of immunity D (years) by time of primary infection (years) and CD4+ specific immunogenic potential (ml).

All graphs in the figure have the same y axis, whose label is reported in the leftmost graph only. In each panel, the color of the lines indicates the infection outcome for secondary infections occurring after memory protection has waned, i.e. at ages just above (age of the latest secondary infection for which memory is protective). If exceeds 100 years, the protection conferred by primary infection is considered lifelong. The curves are discrete because the times of primary and secondary infection have been sampled with a step of 2 years to reduce computational time.