Recombinant Salmonella as vaccine carriers

Summary Live attenuated bacterial vaccines, in particular recombinant Salmonella strains, have several advantages over conventional vaccines. They are able to resist the harsh conditions of the mucosal environment and efficiently cross the epithelial barriers of the digestive, respiratory or genital tracts, thus facilitating their mucosal delivery. In addition, they express mucosal adjuvant activity and are able to survive for several weeks in mucosal tissues, thus providing long-term antigenic stimulation. They can simultaneously express several antigens and the self assembly of viral components into virus-like particles has been documented for human papilloma virus, hepatatis B virus and rotavirus. Administration of such recombinant bacteria to mice via the oral or nasal route can induce neutralizing conformational antibodies and trigger cellular and humoral immune responses both systemically and locally which are specific for the carried antigen. Finally, they are attractive vaccine candidates, as they are cheap and simple to produce.