Abstract: The present invention provides chimeric proteins such as Salivary Binding Protein (SBR) coupled to the B subunit of cholera toxin. Such a chimeric protein, when expressed in attenuated Salmonella typhymurium produces significant increases in serum IgG and salivary IgA antibody levels after oral immunization. In another embodiment of the present invention, the recombinant plasmid contains a salivary binding protein-cholera toxin A2/B chimeric protein expressed in E. coli. Intragastric immunization of SBR coupled to CTB in this chimeric protein form leads to increased antigen responsive T cells. In another embodiment of the present invention, the recombinant plasmid contains a salivary binding protein-cholera toxin.sup..DELTA.A1 chimeric protein expressed in Salmonella typhimurium. Oral immunization using this recombinant plasmid results in increased serum IgG responses to antigen. Oral immunization using this recombinant plasmid also resulted in increased salivary IgA antibody responses to antigen.