International audience ; The COVID-19 pandemic has disrupted societies globally. Public health institutions were tasked with responding to the pandemic in a dynamic and uncertain context. This paper sheds light on the experiences of COVID-19 response actors as they navigated multi-dimensional crises associated with the pandemic in general and vaccine hesitancy in particular. This research was conducted during the initial phase of the COVID-19 vaccine rollout in Flanders, Belgium. Participants included informants across all levels of the COVID-19 vaccination strategy including but not limited to those producing scientific knowledge, providing policy input, or implementing public health directives locally. 'Crisis' was identified as a recurring theme in interviews with informants. The paper highlights multi-dimensional crises experienced by informants such as the: (i) crisis of prioritization, (ii) crisis of communication, (iii) crisis of the changing image of science, (iv) crisis of epistemic agency and autonomy, and (v) crisis of trust.