Protection against inhalation anthrax by immunization with Ty21a stably producing protective antigen of .

The national blueprint for biodefense concluded that the United States is underprepared for biological threats. The licensed anthrax vaccine absorbed vaccine, BioThrax, requires administration of at least 3-5 intramuscular doses. The anthrax vaccine absorbed vaccine consists of complex cell-free culture filtrates of a toxigenic strain and causes tenderness at the injection site and significant adverse events.

Development of a Live Attenuated Bivalent Oral Vaccine Against Shigella sonnei Shigellosis and Typhoid Fever.

Shigella sonnei and Salmonella Typhi cause significant morbidity and mortality. We exploited the safety record of the oral, attenuated S. Typhi vaccine (Ty21a) by using it as a vector to develop a bivalent oral vaccine to protect against S.

Stable expression of Shigella sonnei form I O-polysaccharide genes recombineered into the chromosome of live Salmonella oral vaccine vector Ty21a.

Live, attenuated Salmonella enterica serovar Typhi strain Ty21a, a licensed oral typhoid fever vaccine, has also been employed for use as a vector to deliver protective antigens of Shigella and other pathogens. Importantly, lipopolysaccharide (LPS) alone has been shown to be a potent antigen for specific protection against shigellosis. We reported previously the plasmid cloning of heterologous LPS biosynthetic genes and the expression in Ty21a of either S.

Core-linked LPS expression of Shigella dysenteriae serotype 1 O-antigen in live Salmonella Typhi vaccine vector Ty21a: preclinical evidence of immunogenicity and protection.

Shigella dysenteriae serotype 1 (S. dysenteriae 1) causes severe shigellosis that is typically associated with high mortality. Antibodies against Shigella serotype-specific O-polysaccharide (O-Ps) have been shown to be host protective.