The present invention is related to a method for obtaining antigenic structures with high cross reactivity, able to enhance the immune response to peptidic antigens administered systemically and/or mucosally, as well as with the chemical structures obtained from this method, and with formulations obtained and their uses. The method described in the present invention enables the obtaining of new antigenic structures, starting from the selection and synthesis of dendrimers, which are coupled to carrier molecules. The resulting structures can be used adjuvated conveniently or in a formulation of various antigens. A synergistic effect can be found in the cross reactivity and immunogenicity. Furthermore, the formulations may contain stabilizers and preserves. The antigenic structures of the present invention can be used in the pharmaceutical industry as vaccine formulations to prevent or to treat diseases in humans and animals, as well as in the development of diagnostic systems.