BCG induces long-lasting heterologous Th17 responses. PBMCs isolated from 18 volunteers before and after (2 weeks, 3 months and 1 year) vaccination were stimulated in vitro with sonicated MTB (a, d), heat-killed C. albicans yeast (b, e) and S. aureus (c, f). IL-17 (a-c) and IL-22 (d-f) production was assessed by ELISA in the supernatants. * p < 0.05; ** p < 0.01; *** p < 0.005.