D to G Total IgG ELISA titers expressed as log10 of the mean AUC against indicated viruses in pre-challenge sera in AAV-HA (D, n = 18), AAV-cHA (E, n = 18), AAV-NP (F, n = 11) or WIV (G, n = 18) immunized animals (grey area). Reactivity of sera of AAV-GFP immunized animals is indicated as white area in the center of each web diagram. ELISAs were performed in technical duplicates. 