Abstract: Self-propagating, fusogenic blebs are produced from cells infected with a population of Venezuelan Equine Encephalitis virus replicon particles (VRP). The self-propagating, fusogenic nature of the blebs is derived from expression of heterologous genes encoding viral fusion proteins that are incorporated into the replication defective replicon particles. The resulting blebs can be harvested from supernatants of cells displaying severe cytopathic effects. The blebs are used to make immunogenic compositions and devise methods of immunizing mammals against paramyxoviruses such as parainfluenza virus type 3.

Abstract: The invention generally relates to recombinant polynucleotides, positive-strand RNA virus (psRNAV) recombinant expression vectors, and packaging systems. The packaging systems are based on the expression of helper functions by coinfecting re-combinant poxvirus vectors comprising recombinant polynucleotides. Methods for obtaining psRNAV replicon particles using these packaging systems are disclosed. Immunogenic compositions and pharmaceutical formulations are provided that comprise replicon particles of the invention. Methods for generating an immune response or producing a pharmaceutical effect are also provided.

Abstract: This invention relates to a method for recombinantly producing via rescue canine distemper virus, a nonsegmented, negative-sense, single-stranded RNA virus, and immunogenic compositions formed therefrom. Additional embodiments relate to methods of producing the canine distemper virus as an attenuated and/or infectious viruses. The recombinant viruses can be prepared from cDNA clones, and, accordingly, viruses having defined changes, including nucleotide/polynucleotide deletions, insertions, substitutions and rearrangements, in the genome can be obtained.