The present invention is directed to a recombinant antigen gene, a recombinant antigen protein and a subunit vaccine composition having the same against infection of porcine circovirus type 2 (PCV2). A recombinant antigen gene, which introduces site-directed mutagenesis into the nuclear localization signal (NLS) of open reading frame 2 (ORF2) of PCV2 genome, followed by codon optimization, is expressed by a baculovirus expression system in vitro, thereby preserving the original antigenicity, as well as drastically enhancing expression of the recombinant antigen protein. The recombinant antigen protein can be applied in a subunit vaccine composition, for providing vaccinated animals with better protection ability without suffering the risk of toxicity recovery.本發明係有關於一種抗豬環狀病毒第二型病毒(PCV2)感染之重組抗原基因、重組抗原蛋白及含彼之次單位疫苗組成物,其係於PCV2基因體之開放閱讀框架2(open reading frame 2;ORF2)之核定位訊息序列中導入位點突變並進行密碼子優化,所得之重組抗原基因利用重組桿狀病毒表現系統進行體外表現,不僅保有原始蛋白抗原性,又可大幅提升其重組抗原蛋白的表現量,所得之重組抗原蛋白在應用於次單位疫苗組成物時,可提供受免疫動物較佳的疫苗保護力又不具返毒風險。
