Psychosocial predictors of the innate immune response to influenza vaccination

Experimental activation of the innate immune system has contributed significantly to both our understanding of how psychological factors influence immune function as well as how immune activity influences the brain and behavior. The annual influenza vaccine can be used to interrogate the effects of mild immune stimulation on day-to-day changes in psychological processes in human subjects that range across the lifespan and in both clinical and non-clinical populations. Yet, the immune response to the influenza vaccine in the days immediately following its administration are not well characterized. The present study describes changes in inflammatory and antiviral gene expression within circulating immune cells, plasma cytokines, and C-reactive protein (CRP) following receipt of the flu vaccine, and further reports the association between several common behavioral health factors and the acute immune response. Participants were 65 adults (mean age 18.81 ± 1.03 years; 66.2% female) who provided a blood sample immediately before and then 24 h after receiving the vaccine. A subsample also provided additional blood samples at 48 and 72 h. Plasma was assayed for CRP, IL-6, IL-10, IL-8, TNF-α, and IFN-γ, and peripheral blood mononuclear cell RNA was sequenced for evidence of change in expression of an a priori set of type 1 interferon (IFN) and inflammatory response genes (INFLAM). Plasma cytokines, CRP, and IFN response genes increased 24 h after vaccination, all ps