Abstract: This invention discloses recombinant vectors and live attenuated pathogens produced by these vectors which are useful as vaccines and therapeutic agents. Particularly disclosed are live attenuated recombinant viruses that remain at very low virus loads, and preferably do not persist in the infected hosts. These recombinant viruses are useful against retroviruses such as human immunodeficiency virus and against acquired immunodeficiency diseases. In the recombinant vectors and pathogens, one or more genes, or part of the gene(s), responsible for pathogenesis have been completely or partially rendered nonfunctional, e.g., by full or partial deletion or mutagenesis. Further, the recombinant vectors and pathogens contain one or more genes encoding cytokine(s) and/or lymphokine(s).

Abstract: Vaccines comprising a recombinant vaccinia virus expressing at least two heterologous genes encoding pathogen antigens are described. A first antigen gene is inserted into the thymidine kinase gene of the vaccinia virus and a second antigen gene is inserted into the hemagglutinin gene of the vaccinia virus. In particular, the hemagglutinin and fusion genes of the rinderpest virus have been inserted into the thymidine kinase and hemagglutinin genes of the vaccinia virus, respectively. Such double recombinant viruses have been found to be highly attenuated while remaining effective in protecting an inoculated host.