As observed with pertussis, statistically significant induction of CD25 (Fig. 1E), CD25/IFN-γ (Fig. 1F), and CD107a (Fig. 1G) was observed in response to restimulation with H1N1 Ag, and IL-2 blocking significantly decreased CD25/IFN-γ expression (Fig. 1F), whereas IgG depletion inhibited the degranulation (CD107a) response (Fig. 1G). The gene discussed is IFNG; the disease is pertussis.