Live bacterial vaccines for viral infection prophylaxis or treatment

A live Salmonella bacterium, comprising:

• a deletion of at least one IS200 element;
• a P22 phage C2 repressor which is constitutively expressed without dependence on a presence of an activator or inducer molecule;
• a stabilized DNA construct having a promoter sequence and encoding a fusion peptide, said fusion peptide comprising a bacterial secretion peptide portion and a non-bacterial immunogenic polypeptide portion, wherein the DNA construct has a nucleotide sequence coding for the non-bacterial immunogenic polypeptide portion which has at least one codon optimized for bacterial expression with respect to its non-bacterial counterpart, wherein the DNA construct is stabilized against transduction of other bacteria;
• and
• said bacterium having a secretion mechanism which interacts with at least the bacterial secretion peptide portion to cause a secretion of the fusion peptide from the bacterium;
• the bacterium having a genetic virulence attenuating mutation and being adapted to act as an animal vaccine, to transiently infect a tissue of the animal, and cause an immune response to the non-bacterial immunogenic polypeptide portion to cause an immunity in the animal to a non-bacterial organism associated with the non-bacterial immunogenic polypeptide portion.

A live bacterium, comprising:

• a stabilized DNA construct integrated into a Salmonella bacteria chromosome, having a promoter sequence and encoding a fusion peptide, said fusion peptide comprising a bacterial secretion peptide portion and an Influenza immunogenic polypeptide portion, wherein the DNA construct has a nucleotide sequence coding for the Influenza immunogenic polypeptide portion which has at least one codon optimized for Salmonella expression with respect to its Influenza counterpart, wherein the DNA construct is stabilized against transduction of other bacteria;
• genetic modifications with respect to a wild type Salmonella effective to substantially prevent new infections by bacteria phage and prevent subsequent phage transductions by bacteria phage, comprising at least a deletion of at least one IS200 element of the live Salmonella bacteria chromosome, and a constitutively expressed P22 phage C2 repressor without dependence on a presence of an activator or inducer molecule;
• and
• said bacterium having a secretion mechanism which interacts with at least the bacterial secretion peptide portion to cause a secretion of the fusion peptide from the bacterium;
• the bacterium having a genetic virulence attenuating mutation and being an animal Influenza vaccine, which causes a localized transient intestinal epithelial tissue infection of the animal, and induces an immune response to the Influenza immunogenic polypeptide portion to create an immunity in the animal to an Influenza strain corresponding to the Influenza immunogenic polypeptide portion.