FIG. 5.
S. typhi-specific antibodies in serum after oral (n = 5) or rectal (n = 11) immunization with S. typhi Ty21a. The bars indicate geometric mean concentrations (±SEM) of specific IgA, IgG, or IgM antibodies (ab) in serum before and after immunization. Significant increases from preimmune levels are indicated with asterisks.