To provide novel viral vectors in which the expression of viral genes is regulated in such a way that it is functional in a complementation cell and non-functional in a host cell, as well as viral particles and host cells containing the novel vectors, and also a complementation cell including a viral gene expression repressor and a method for preparing infectious viral particles. 発現が相補細胞で機能性だが宿主細胞で機能性でないようにウイルス遺伝子の発現が調節された新規ウイルスベクターと、その新規ベクターを含んだウイルス粒子および宿主細胞を提供することである。 - 特許庁