Vaccine for prophylaxis or treatment of an allergen-driven airway pathology

1. A method for reducing serum levels of immunoglobulin E (IgE) antibodies specific for an antigen to which a subject has been sensitized, the method comprising infecting the antigen-sensitized subject's respiratory tract with a live Bordetella pertussis strain which is deficient for tracheal cytotoxin (TCT), pertussis toxin (PTX), and dermonecrotic toxin (DNT), wherein the step of infecting the antigen-sensitized subject's respiratory tract with the live Bordetella pertussis strain reduces the subject's serum levels of IgE.

2. The method of claim 1 , wherein the strain comprises a mutated pertussis toxin (ptx) gene, a deleted or mutated dermonecrotic (dnt) gene, and a heterologous ampG gene.

3. The method of claim 2 , wherein the heterologous ampG gene is an E. coli ampG gene that replaces the wild-type Bordetella strain ampG gene.

4. The method of claim 2 , wherein the mutation of the ptx gene comprises a substitution of an amino acid involved in substrate binding and/or an amino acid involved in catalysis.

5. The method of claim 4 , wherein the substitution of the amino acid involved in substrate binding comprises R9K and the substitution of the amino acid involved in catalysis comprises E129G.

6. The method of claim 2 , wherein the heterologous ampG gene is the only heterologous gene in the strain.