Using a network approach, we addressed in two studies interrelations among potential antecedents of vaccine intentions, related to both COVID-19 risk perception and epistemic beliefs (i.e., trust in scientists and conspiracy beliefs). In Study 1 and 2, we assessed a US (N = 994) and an international sample (N = 902) during spring and summer 2020. The network analysis reveals a complex interplay of factors where trust in scientists, the closest predictor of vaccine intention, is associated with conspiracy beliefs and danger perception. Furthermore, we found evidence for unrealistic optimism, with participants perceiving the risk of getting infected with COVID-19 as lower compared to the risk they attributed to other people. However, this bias was not associated with vaccine intention. Study 2 corroborated these results. The results call for a global change in the narrative which should highlight the epistemic authority of science in order to build a stronger trust in the scientific community. However, tackling trust in scientists needs a wider field of persuasion that includes conspiracy beliefs and risk perception factors.