Incapacitated whole-cell immunogenic bacterial compositions produced by recombinant expression

A method of producing an immunogenic bacterial composition, comprising the steps of:

• producing incapacitated bacteria by introducing an expression vector into the bacteria, the expression vector comprising a bacteriophage promoter operably linked to a polynucleotide encoding a gene product wherein the bacteria are recombinantly modified to express a bacteriophage RNA polymerase for transcription from the bacteriophage promoter, wherein expression of the gene product is at a level sufficient to render the bacteria incapacitated;
• and
• optionally adding a pharmaceutically acceptable excipient, thereby producing an immunogenic bacterial composition;
• wherein
• (i) the bacteriophage promoter is a T7 bacteriophage promoter and the bacteriophage RNA polymerase is T7 RNA polymerase,
• (ii) the bacteriophage promoter is a SP6 bacteriophage promoter and the bacteriophage RNA polymerase is SP6 RNA polymerase,
• (iii) the bacteriophage promoter is a T3 bacteriophage promoter and the bacteriophage RNA polymerase is T3 RNA polymerase, or
• (iv) the bacteriophage promoter is a T7 bacteriophage promoter and the bacteriophage RNA polymerase is T7 RNA polymerase.