Antigen delivery by attenuated Bacillus anthracis: new prospects in veterinary vaccines.

This report summarizes the recent investigations on the use of Bacillus anthracis as a live vector for delivery of antigens. Recombinant strains were constructed by engineering the current live Sterne vaccine. This vaccine, used to prevent anthrax in cattle, causes side-effects due to anthrax toxin activities. Bacteria producing a genetically detoxified toxin factor were devoid of lethal effects and were as protective as the Sterne strain against experimental anthrax. Moreover, B. anthracis expressing a foreign antigen controlled by an in vivo inducible promoter were able to generate either antibody or cellular protective responses against heterologous diseases.