Sneddon-Wilkinson disease, also known as subcorneal pustular dermatosis (SPD), is a rare disease characterized by vesicles or pustules that may rapidly expand and coalesce. Idiopathic in nature, SPD's clinical presentation of "half-half" blisters, with half of each blister containing pus and half containing clear fluid, is characteristic of this disease. We describe a previously healthy 21-year-old man who developed acute pustular vesicular eruptions consistent with SPD eight days following the Moderna COVID-19 vaccination.