FIG. 3.

Box plots of serum IgG1 and IgG2a antibody levels to HDS after i.n. administration of PLGA-HDS with CT or R192G LT (dLT). Groups immunized i.n. are designated as control (C; unloaded PLGA microparticles and CT), CT (PLGA-HDS microparticles plus CT), or dLT (PLGA-HDS microparticles plus R192GLT). Primary (1°) serum measurements were made on day 24 for CT rats and on day 26 for dLT rats. Tertiary (3°) serum measurements were made on day 211 for CT rats and on day 188 for dLT rats. Boxes enclose the 25th to 75th percentiles, and lines within the boxes indicate the median values. The levels of significance beneath the x axes were calculated with respect to the primary response levels.