FIG 2.

Detection of B. pseudomallei-specific antibody titers. C57BL/6 mice (n = 10 per group) were immunized with either PBS (control) or PBK001 vaccine (1.5 × 10⁴ CFU). Serum samples were collected from individual vaccinated mice 2 weeks after the last boost, and serum IgG (A), IgG1 (B), and IgG2a (C) against B. pseudomallei whole cells were analyzed by indirect ELISAs. Antibody levels were reported as the reciprocal of the highest titer giving an optical density (OD) reading of at least the mean plus 2 SD of baseline sera and analyzed via the Mann-Whitney test. The limit of detection (LOD) is 50 (horizontal dotted line). Bars represent means with standard error of the mean (SEM). Values that are significantly different are indicated by bars and asterisks as follows: ****, P < 0.0001; *, P < 0.05.