Chronic stress can impair immune function, including immune response to vaccines. This has important implications for cancer control and prevention because tumor vaccines are emerging as tools for cancer treatment and prevention, and the cohort that would benefit from the vaccines is likely to be stressed. Women at elevated risk for breast cancer experience significant levels of distress that have been associated with immune function decrements. Interventions to treat distress-related immune decrements among these women are needed because these women will be among the first candidates for breast cancer vaccines. In theory, stress-management interventions should improve immune function and response to vaccines, but the findings to date are mixed, in part because most intervention studies have been done with medical patients who by nature have immune confounds. Thus, it is unknown how stress management interventions affect immune function in stressed but otherwise healthy people, such as women at elevated risk for breast cancer.