Fig. 2

Results from immunization of BALB/c mice with 100 µg pCMV(A)-S in saline by various routes. Each bar represents the group geometric mean titer (GMT) determined by end-point dilution ELISA assay for HBsAg-specific antibodies (anti-HBs) of IgG1 (gray bars) or IgG2a (black bars) isotypes in plasma taken 4 weeks (A) and 8 weeks (B) after immunization. Titers were defined as the highest plasma dilution resulting in an absorbance value two times that of nonimmune plasma, with a cut-off value of 0.05. Numbers above each bar indicate the IgG2a-to-IgG1 ratio, with a value >1 indicating a more Th-1 like response.