RationaleVaccination willingness is a critical step in the effort to reach herd immunity and control the COVID-19 pandemic. Nevertheless, many people remain reluctant to be vaccinated.ObjectiveIntegrating the literature on Self-Determination Theory, trust in authorities, and conspiracy theories, this research examines (a) the direct and indirect effect of government trust and conspiracism via underlying forms of motivations for (not) getting vaccinated against COVID-19 and (b) whether these associations differ across the two largely politically independent Belgian linguistic groups.MethodsUsing Structural Equation Modeling, we tested our models in two independent samples, in February 2021 (T1) and April 2021 (T2) (Total N = 8264).ResultsAt T1 and T2, Government trust and conspiracism both predict COVID-19 vaccination intention, respectively positively and negatively. These relations are fully mediated by motivational factors, with identified motivations having a larger positive contribution. Looking at linguistic context, differences emerge at T2, with French-speaking Belgians showing lower levels of government trust and higher levels of conspiracism than Dutch speakers.ConclusionsResults highlight the importance of integrating distal (trust in government, conspiracism) and proximal (motivational) variables to understand vaccination intentions. ; SCOPUS: ar.j ; info:eu-repo/semantics/published