Most countries in the world deploy scientific advances developed abroad. Do people accept or reject these advances based on their origins, particularly for new and poorly understood breakthroughs such as the COVID vaccine? We argue that people rely on their preexisting attitudes toward the vaccine’s country of origin when assessing the desirability of the vaccine itself, thereby substituting an easy judgment task for a harder one. We study the effect of source information on COVID vaccine hesitancy in Lebanon with a cueing experiment that treats subjects with the vaccine’s country of origin. We find wide variation in baseline levels of skepticism across vaccines, but, consistent with expectations, hesitancy drops dramatically with favorable predispositions toward the source. Yet we also find suggestive evidence that baseline hesitancy rates vary according to simple familiarity with the vaccines themselves rather than something inherent to the country sources. In short, subjects give the benefit of the doubt to sources they view favorably, even as they grapple with the harder question about the safety and efficacy of the vaccines themselves.