The notion of an 'ignorant public' is attributed in outbreak scenarios through vaccination narratives that are institutionally reinforced by governments and the media across different contexts. The ignorant public narrative is a discursive shift that reduces public concerns about vaccines to a lack of knowledge, obscuring how these concerns are indicative of mistrust and anxiety or efforts to counter the dominance of acceptable and legitimate knowledge. This narrative risks a deflection of challenges in the structural determinants of vaccine uptake and depoliticise rumours and mistrust that arise during vaccination campaigns. Examples from Sierra Leone, Uganda, and India show how 'ignorant public' framings are used as explanation for vaccine hesitancy through assigned roles for institutions and publics, and the consequences this narrative has for vaccination encounters. These examples are based on ethnographic fieldwork and media analysis carried out before, during, and after outbreaks, of newly introduced vaccines for both human and animal health. Drawing on science communication and development studies, we show how this narrative then positions governmental concern about vaccine hesitancy as being a (largely) imagined issue of public ignorance. We argue that when institutions tasked with strengthening vaccine uptake see public ignorance as the key problem, this can obscure other problems, such as competing interests and experiences, and also minority group treatment. As a result, public governance is rationalised by assigning the ignorance label to certain public groups that stand in contrast to scientific and government expertise, and so accountability for low vaccine uptake is transferred onto the public.