Figure 1.

Surface antigen AgI/II-specific immunoglobulin G (IgG) in serum(a)and AgI/II-specific and total IgA levels in saliva(b)on day 27 following intragastric (i.g.) immunization of groups of mice (n = 4) on days 0, 10 and 20. Data are represented as geometric mean and standard deviation (a) or antibody responses from individual animals (b; closed symbols, specific IgA; open symbols, total IgA). The line denotes the lowest detectable limit of 0·5 µg/ml. SBR, saliva-binding region; CT, cholera toxin; SBR-CTA2/B, a genetically coupled protein composed of the SBR of the Streptococcus mutans surface antigen AgI/II and the non-toxic A2 and B subunits of CT; SBR+CT, recombinant SBR admixed with CT; SBR-CTB, SBR chemically coupled to the recombinant CT B subunit; Sham, buffer only.