IL1B and influenza: In early childhood, the relative immaturity of pathogen-recognition pathways results in an altered cytokine profile during influenza infection, with reduced production of IL-12 and IFN-γ—key mediators of antiviral defence—and, conversely, higher levels of pro-inflammatory cytokines such as IL-6 and IL-1β, as well as the anti-inflammatory cytokine IL-10.