Photomicrographs of lung tissue from Balb/c mice to evaluate eosinophil infiltration after challenge with SARS-CoV that had previously been immunized with RBD219-N1 formulated with (A) Alhydrogel® (Al), (B) AddaVax (MF59-like adjuvant), and (C) no adjuvant. (A) Alhydrogel® (Al): Perivascular mononuclear infiltrations (lymphocytes and monocytes/macrophages) along with very few eosinophils, only one seen in this field, indicated by a red arrow. (B) AddaVax (MF59-like adjuvant): Severe inflammatory infiltrations with more than 50% eosinophils, red arrows highlight some of those, and (C) no adjuvant: Inflammatory infiltrations with less than 50% eosinophils. Scale bar = 100 μm.