This paper examines the case of Ebola, ça Suffit trial which was conducted in Guinea during Ebola Virus Disease (EVD) outbreak in 2015. I demonstrate that various non-epistemic considerations may legitimately influence the criteria for evaluating the efficacy and effectiveness of a candidate vaccine. Such non-epistemic considerations, which are social, ethical, and pragmatic, can be better placed and addressed in scientific research by appealing to non-epistemic values. I consider two significant features any newly developed vaccine should possess; (1) the duration of immunity the vaccine provides; and (2) safety with respect to the side effects of the vaccine. Then, I argue that social and ethical values are relevant and desirable in setting the parameters for evaluating these two features of vaccines. The parameters that are employed for setting up the criteria for assessing the features might have far-reaching implications on the well-being of society in general, and the health conditions of several thousand people in particular. The reason is that these features can play a decisive role during the evaluation of the efficacy and effectiveness of the vaccine. I conclude by showing why it is necessary to reject the concept of epistemic priority, at least when scientists engage in policy-oriented research.
Keywords: Ebola; Epistemic priority; Non-epistemic values; Science and values; Underdetermination; Ça Suffit trial.