The widespread threat of contagious disease disrupts not only everyday life but also psychological experience. Building on findings regarding xenophobic responses to contagious diseases, this research investigates how perceived vulnerability to a disease moderates the psychological link between people’s xenophobic thoughts and support for ingroup-protective actions. Three datasets collected during the time of Ebola ( N = 867) and COVID-19 ( Ns = 992 and 926) measured perceived disease risk, group-serving biases (i.e., xenophobic thoughts), and support for restrictive travel policies (i.e., ingroup-protective actions). Using correlational and quasi-experimental analyses, results indicated that for people who perceive greater disease risk, the association between group-serving bias and restrictive policy support is weakened. This weakened association occurred because people who felt more vulnerable to these diseases increased support for ingroup-protective actions more strongly than xenophobic thoughts. This research underscores the importance of understanding the impact of threats on psychological processes beyond the impact on psychological outcomes.