Adjuvant compositions, vaccines, constructs for preparing the adjuvant compositions and vaccines and methods of using the adjuvant compositions and vaccines to enhance immune responses in subjects are provided herein. In particular, a rapid antibody response to the vaccine including both IgG (in the circulation) and sIgA (mucosal secretory IgA) is elicited. The adjuvants and vaccines may be used for sub-cutaneous or mucosal administration enabling low cost, effective vaccination of subjects. A method of epitope mapping to rapidly identify antigenic epitopes is also provided.