B Significant peptides identified in the epitope screen with AAV-HA pooled pre-challenge serum ((AAV-HA, -cHA, -GFP, WIV n = 18, AAV-NP n = 11; data shown in Fig.EV2) were mapped onto HA1 (red) and HA2 (blue) of the trimeric HA (PDB 3UBE generated with PyMol) (n = 3, technical duplicates). The position of the RBS (yellow) and the C179 epitope (dashed line) is marked. 