Can Stress Make You Sick? The Effect of Cardiovascular Reactivity to and Recovery from Stress on Immune Response

From folklore and mass media to empirical research, stress has long been seen to weaken an individual’s immune system, rendering them vulnerable to disease. This study asks, “How do individuals’ reactions to and recovery from stressful events affect their susceptibility to disease?” It was hypothesized that individuals who display greater reactivity to a laboratory stress-task and slower recovery would have weaker immune function. As part of the Vaccination Immunity Project, I have been given access to data for 153 participants measuring their cardiovascular stress reactivity and recovery and their immune response to an immunization. Stress reactivity and recovery were measured as changes in heart rate and blood pressure in response to a laboratory stress-task simulating public speaking. Immune response was examined by measuring production of antibody in response to the standard Hepatitis B vaccine series. The stressor task caused significant increases in the cardiovascular markers, which returned towards baseline during the recovery period. Both the reactions of their cardiovascular markers and their recovery to baseline were highly correlated across two stress sessions approximately four weeks apart. Neither individual differences in stress reactivity nor recovery was found to significantly predict antibody response to the Hepatitis B vaccine. The effect of diastolic blood pressure on second antibody response and cardiovascular recovery on third antibody response approached significance. The findings on stress and the immune system conflict with previous research thus demonstrating the complexity of the association between stress and immunity and the difficulty in measuring and operationalizing these variables