Antigen delivery system

A protein delivery vehicle comprising:

• a live avirulent Salmonella typhimurium having a type III secretion system, said Salmonella typhimurium comprising a nucleic acid molecule comprising a promoter operably linked to a segment encoding a chimeric protein, the chimeric protein comprising a protein of interest or an immunogenic portion thereof and an injectable protein secretable by the type III secretion system or an injectable portion thereof.

A chimeric protein comprising:

• a first amino acid sequence of an injectable protein secretable by a type III secretion system or an injectable portion thereof;
• and
• a second amino acid sequence of a protein of interest or immunogenic portion thereof introduced into the first amino acid sequence of the injectable protein or injectable portion thereof.

A chimeric nucleic acid molecule comprising:

• a first nucleic acid sequence encoding an injectable protein which is secretable by a type III secretion system or an injectable portion thereof;
• and
• a second nucleic acid sequence encoding a protein of interest or immunogenic portion thereof introduced into the first nucleic acid sequence of the injectable protein or injectable portion thereof, the second nucleic acid sequence being introduced so as to produce a chimeric nucleic acid molecule encoding a chimeric protein comprising the protein of interest or immunogenic portion thereof and the injectable protein or injectable portion thereof.