Recombinant vaccinia viruses as live vaccines

Recombinant vaccinia viruses can be constructed that express foreign antigens. These viruses retain their infectivity and synthesise the foreign gene product in tissue culture and in vaccinated animals. Following vaccination, specific antibody and cell-mediated immune responses are generated against the foreign protein and in several cases these have protected the animal against subsequent challenge with the corresponding pathogen. The potential use of recombinant vaccinia viruses as medical or veterinary vaccines is discussed.