Abstract: The present invention provides a method of increasing expression of a promoter distal gene in a virus of the order Mononegavirales, and a recombinant virus constructed by such method. Also provided is a method of attenuating a virus of the order Mononegavirales, and of constructing an attenuated virus useful for a vaccine.

Abstract: Provided is a method of attenuating a virus of the order Mononegavirales, comprising the step of: rearranging said virus' gene order by moving a gene essential for RNA replication away from its wild-type 3' promoter proximal position site, wherein said gene is an essential limiting factor for genome replication and is placed in the next to last position in the gene order. Also provided is a method of making an attenuated virus useful for a vaccine, comprising the steps of: rearranging said virus' gene order by moving a gene essential for RNA replication away from its wild-type 3' promoter proximal position site, wherein a gene which is a n essential limiting factor for genome replication is placed in the next to last position in the gene order; and placing a gene coding for an immune response inducing antigen in the position closest to the 3' end of the gene order. Also provided is a method of attenuating a virus of the order Mononegavirales, comprising the step of: rearranging said virus' gene order.