Fig. 1.

ELISA values of pooled mouse sera following immunizations with A33 and L1 proteins combined with different adjuvants. Mice (n = 5) were immunized twice with a mixture containing 10 μg each of A33 and L1 proteins (AL) alone or combined with alum, alum + CpG, MPL + TDM (MPL) or QS-21 and challenged with VACV strain WR at 3 weeks after the last immunization. Serum was collected prior to immunization (week 0), 3 weeks following immunizations 1 and 2 (shaded area), and 2 weeks after challenge (unshaded area). Antibodies to A33 (A) and L1 (B) were determined on pooled sera by ELISA and reciprocal endpoint values are plotted. In panel B, the plots for AL + QS-21 and for AL + alum + CpG are superimposed. Serum collected 3 weeks after the second immunization was re-analyzed for IgG1 or IgG2a isotype antibodies to A33 (C) and L1 (D). In the latter panels, alum and CpG are abbreviated as A and C, respectively.