An immunogenic composition includes an immunogene and an adjuvant additive. The adjuvant additive includes a receptor associated protein (RAP) having an amino acid sequence of SEQ ID NO:1 and/or a pseudomonas exotoxin A (PE) protein. The immunogenic composition including the adjuvant additive is used in a method of enhancing immune response in hosts, whereby antibody immune response and cellular immune response for the hosts may be successfully induced and enhanced by the immunogenic composition.
