Consistent with prior observations (3, 6), responses to pertussis and H1N1 were significantly augmented by LCC IL-12 and IL-18 (p ≤ 0.0001 for all parameters), indicating that in vitro accessory cell activation and production of IL-12 and IL-18 (which is essential for IL-2–mediated NK cell activation) (3, 5, 32) were suboptimal. The gene discussed is IL2; the disease is pertussis.