GZMB and infection: Similar to the influenza type-specific response following natural infection with A/H3N2, B-LCII cases showed a significant increase in B/Lee-stimulated GrB activity compared to the No-LCII subset at 20-weeks post-vaccination; B-LCII: 1683 (1272, 2194) vs No-LCII: 774 (734, 815) (Figure 2C, right panel; Supplemental Table S2; p < 0.001).