During emerging public health crises, both policymakers and members of the public are looking to scientific experts to provide guidance. Even in cases where there are significant uncertainties, there is pressure for experts to “speak with one voice” to avoid confusion, allow officials to make evidence-based decisions rapidly, and encourage public support for such decisions. This can lead experts to engage in masking of information about the state of the science or regarding assumptions involved in policy recommendations. Although experts might (...) have good reasons for masking disagreements, uncertainties, or assumptions when offering policy advice, we argue that this strategy can result in epistemic harms. Using the case of the COVID-19 pandemic, we show that public health authorities masked two types of information necessary for laypersons to evaluate public health recommendations: (1) experts’ disagreements about the scientific evidence and (2) the role of values in making inferences from the science to policy positions. We contend that this resulted in epistemic harms against laypeople that provide a pro tanto case against masking information. We further argue that when the science is in flux and policies need to be implemented despite significant uncertainties, there is an all-things-considered case against masking the types of information discussed. (shrink)