Psychological stress reactions to the COVID-19 pandemic are complex and multifaceted. Research provides evidence of a COVID Stress Syndrome, consisting of worry about the dangerousness of getting infected with SARSCoV2 and coming into contact with infected surfaces, worry concerning the personal socioeconomic consequences of COVID-19, xenophobic fears that SARSCOV2 is being spread by foreigners, COVID-19-related traumatic stress symptoms, and compulsive checking and reassurance-seeking about COVID-19. Little is known about how these symptoms are related to vulnerability and protective personality factors. Based (...) on data from 1,976 US and Canadian adults, we conducted a prospective network analysis in which personality factors were initially assessed at Time 1 and then symptoms of the CSS were assessed at Time 2, 2.5 months later. Results indicated that trait optimism and trait resilience were negatively associated with negative emotionality, suggesting a modulatory influence. Negative emotionality was positively linked to the narrower traits of intolerance of uncertainty and health anxiety proneness. These narrower traits, in turn, were prospectively linked to symptoms of the CSS. Results suggest that the effects of broad personality traits on symptoms of the CSS were mediated by narrower traits such as the intolerance of uncertainty. Treatment implications are discussed. (shrink)