IFNG and influenza: As was shown previously40,44, a more plausible explanation is that these CD8+ VM-like cells were activated to produce IFNγ by the inflammatory cytokines elicited by the influenza vaccine (e.g., via IL-12 or IL-6 produced by monocytes or dendritic cells after they were stimulated by components of the influenza vaccine)45 in an antigen-independent manner.