A fusion protein comprising an antigen-presenting cell (APC)-binding domain or a CD91 receptor-binding domain, a translocation peptide, a fusion antigen, an endoplasmic reticulum retention sequence, and optionally a nuclear export signal is disclosed. The fusion antigen comprises a porcine reproductive and respiratory syndrome virus (PRRSV) ORF7 antigen, a PRRSV ORF1b antigen, a PRRSV ORF6 antigen, and a PRRSV ORF5 antigen. The fusion protein is useful for inducing antigen-specific cell-mediated and humoral responses.本發明提供一種融合蛋白，其包含一抗原呈現細胞(APC)結合區域或一CD91受體結合區域、一轉位胜肽、一融合抗原、一內質網滯留序列以及屬於隨選性之一出核訊號。該融合抗原包含一豬生殖與呼吸綜合症病毒(PRRSV) ORF7抗原、一PRRSV ORF1b抗原、一PRRSV ORF6抗原以及一PRRSV ORF5抗原。該融合蛋白可用於誘發抗原特異性細胞中介及體液性反應。
