In this article, we explain how the COVID-19 wicked crisis context influences the quality of critically needed epistemic policy learning and undermines policy effectiveness. We explore those influences on two main dimensions: Vertically (pertaining to the selection of core scientific advice) and horizontally (pertaining to managing scientific interdisciplinarity). We apply the concept using COVID-19 policy responses from England and Belgium, offer an explanatory framework, and provide recommendations for policymakers, including (i) Crafting a policy-science-public narrative maintaining independence, openness, and trust. (ii) Outlining the limitations of science and public expectation setting. (iii) Enhancing interdisciplinarity in policy formulation by utilizing boundary and discipline-spanning structures, and systems thinking mechanisms for dynamic problem synthesis
