The present invention relates to a Sendai virus or recombinant Sendai virus vector. In particular the present invention provides methods, vectors, formulations, compositions, and kits for a modified Enders strain Sendai viral vector. An immunogenic vector can be used in any in vitro or in vivo system. Moreover, some embodiments include vectors for imaging virus growth, location and transmission.

An objective of the present invention is to provide an improved negative-strand RNA viral vector and a use thereof, the negative-strand RNA viral vector exhibiting transient high expression of genes loaded in the vector and enabling the rapid removal of the vector after said expression. It was discovered that by adding a micro-RNA target sequence to the NP, P, or L gene of a negative-strand RNA viral vector, it is possible to control the expression of the vector depending on the micro-RNA expressed by the introduction cell. In particular, when a micro-RNA target sequence was added to the NP or P gene, the expression of the vector decreased depending on the micro-RNA, and the removal of the vector was promoted, while the effect was reversed when a micro-RNA target sequence was added to the L gene. The vector can be applied in cell therapy and regenerative medicine and can be used as a therapeutic vector that targets cancer.

The present invention provides a temperature-sensitive negative-strand RNA virus or virus vector and an RNA genome thereof. According to the invention, provided is a negative-strand RNA virus or virus vector having a negative-strand RNA genome wherein the phosphoprotein (P protein) on the RNA genome has an amino acid mutation(s) corresponding to a substitution(s) in an amino acid(s) of the P protein corresponding to one or more or all of D433, R434, and K437 and optionally further has an amino acid mutation corresponding to a further amino acid substitution in an amino acid of the P protein corresponding to L511.