T cells from convalescent humans produce IFN-γ, TNF-α, IL-2, IL-17, and IL-22 indicating these cytokines are elicited by natural infection or vaccination and therefore should be further assessed for their role in protective immunity in animal models (Karttunen et al., 1991; Surcel et al., 1991; Ericsson et al., 1994; Salerno-Gonçalves et al., 2009; Paranavitana et al., 2010; Eneslätt et al., 2012). Here, IFNG is linked to infection.