||Inflammation is associated with poorer vascular function, with evidence to suggest that inflammation can also impair the vascular responses to mental stress. This study examined the effects of vaccine-induced inflammation on vascular responses to mental stress in healthy participants. Eighteen male participants completed two stress sessions: an inflammation condition having received a typhoid vaccination and a control (non-inflamed) condition. Tumor necrosis factor-alpha and interleukin-6 (p's < .001) increased following vaccination, confirming modest increases in inflammation. Mental stress increased blood flow, blood pressure, heart rate, and cardiac output in both conditions (all p's < .001), but the blood flow response to stress was attenuated having received the vaccination compared to the control condition (p's < .05). These results further implicate the interaction between inflammation and the vasculature as a mechanism through which stress may trigger myocardial infarction.