The present invention relates to the modification of a live attenuated strain of Salmonella enterica serovar Typhi, wherein its natural surface-exposed polysaccharide and flagellin antigens may be converted to, or augmented by, those from other strains of Salmonella, including S. enterica serovars Paratyphi, Typhimurium and Enteritidis. The present invention also relates to modified strains of Salmonella enterica serovar Typhi being suitable for use as components of a vaccine for enteric fever and salmonellosis.

The present invention relates to an immunogenic composition for Proteobacteria protection and reduced transmission. We have identified Proteobacteria serovar variant combinations that generate an immune response capable of robustly driving bacterial enteropathogens into an evolutionary dead end and reducing the transmission of the bacterium. These inactivated immunogenic positions and typically oral vaccines are easy to apply, cheap to produce, and can be stored long-term without cold-chain requirements making them ideal for application in livestock, or in resource-poor areas. They are believed to be the only immunogenic compositions and vaccine formulations capable of breaking the chain of transmission for these types of pathogen.

Vaccine compositions including a yeast comprising an immunostimulatory polypeptide and optionally an antigenic polypeptide are provided herein. The immunostimulatory polypeptide and the antigenic polypeptide are expressed or displayed on the surface of the yeast vaccine composition. Methods of using the vaccine composition to vaccinate subjects are also provided.

Described is a method for the generation of a live vaccine containing stable bacteria carrying at least three attenuating mutations and a vaccine containing bacteria obtained by said method.

The present invention relates to a vaccine suitable for immunisation against influenza, plague or Y. pestis infection said vaccine comprising outer membrane vesicles (OMVs) and the plague vaccine including the V and/or F1 antigens of Y. pestis.

Provided herein is a Formulation of OmpA including a) OmpA protein as active molecule obtained as a product of OmpA gene inserted in a plasmid comprising a novel set of forward and reverse primer set, and b) Alginate chitosan nanoparticles as vehicle.

Methods for the preparation of polymeric films which encase and preserve bioactive agents. In particular, the invention is directed to the preparation of oral thin films containing bioactive proteins or viruses. For example, methods and compositions are disclosed for preservation of rotavirus and antibodies in thin dry films.

Provided are surprisingly effective methods for inactivating pathogens, and for producing highly immunogenic vaccine compositions containing an inactivated pathogen rendered noninfectious by exposure to a Fenton reagent, or by exposure to a Fenton reagent or a component thereof in combination with a methisazone reagent selected from the group consisting of methisazone, methisazone analogs, functional group(s)/substructure(s) of methisazone, and combinations thereof. The methods efficiently inactivate pathogens, while substantially retaining pathogen antigenicity and/or immunogenicity, and are suitable for inactivating pathogens, or for the preparation of vaccines for a wide variety of pathogens with genomes comprising RNA or DNA, including viruses and bacteria. Also provided are highly immunogenic inactivated vaccine compositions prepared by using any of the disclosed methods, and methods for eliciting an immune response in a subject by administering such vaccine compositions.

This invention relates to the delivery of heterologous peptides or proteins such as therapeutic peptides, therapeutic proteins or antigens to mucosal sites using vesicles derived from the outer membrane of commensal bacteria, recombinant bacteria capable of producing such vesicles, and methods for the production of such vesicles. The invention further relates to an inducible expression system for use in recombinant bacteria.

Provided herein are engineered Salmonella enterica serovar Typhimurium strains and compositions, including vaccines, thereof. Also provided herein are methods of treating and/or preventing infection by at least Salmonella enterica serovar Typhimurium in a subject in need thereof by administering a vaccine provided herein.