Uses of vaccinia virus in vaccine delivery

The construction of vaccinia-based vaccines has been hampered by a lack of information on both the mechanisms of vaccinia-induced immunity in humans and the effect of prior exposure to vaccinia on the course of an immune response to a non-vaccinia antigen. Recent studies have investigated the immune responses induced by this virus in humans and the ability of recombinant viruses to successfully induce immunity to diverse pathogens with diverse routes of infection. In addition to the previously described ability of vaccinia to induce immune responses in experimental animals, the virus has been shown to encode modulators of immune function that may, in the future, permit the use of virus to induce qualitatively different immune responses to particular heterologous antigens.