Anti-Qβ development was assessed using an enzyme-linked immunosorbent assay. 96-well plates (Corning, product 3590) were coated with vidutolimod. Serum samples and monoclonal anti-Qβ (clone Qb5) standard were incubated overnight at 4°C, and human antibodies were detected using goat anti-human Ig-HRP (SouthernBiotech, catalog no. 2010-05). Plates were developed with 3,3′,5,5′-tetramethylbenzidine (Sigma-Aldrich, catalog no. T8665), and anti-Qβ concentrations were calculated from the standard curve generated with monoclonal anti-Qβ antibody (clone Qb5l ref. 14 (link)).