A porcine circovirus type-2 (PCV2) immunogenic composition includes an antigenic peptide. The antigenic peptide is a non-arginine-rich peptide of a PCV2 open reading frame 2 (ORF2) and/or a recombinant fusion protein having the non-arginine-rich peptide of the PCV2 ORF2, a PE peptide, and a KDEL signal peptide. The number of arginines of the non-arginine-rich peptide of the PCV2 ORF2 is not greater than half of the number of arginines of the arginine-rich domain of the N terminal of the PCV2 ORF2.