Self assembled, defective, nonself-propagating viral particles

A pharmaceutical composition, comprising a self-assembled, defective nonself-propagating viral particle produced by a eukaryotic host cell transformed by a avipox virus vector, said avipox virus vector having inserted therein, at least two DNA sequences from a single species of lentivirus DNA sequences wherein one of the lentivirus DNA sequences is selected from the group consisting of the gag gene and gag-pol gene and portions thereof, such that the lentivirus DNA sequences express gag, gag-pol proteins, and portions thereof, referred to as said first lentivirus DNA sequence and a second lentivirus DNA sequence encoding another lentiviral protein, in the eukaryotic host cell infected with the pox virus vector, wherein the lentivirus proteins or portions thereof, self-assemble into defective, non-self-propagating lentivirus particles, in a pharmaceutically acceptable vehicle.