Described herein are recombinant Kluyveromyces lactis (K. lactis) yeasts which are capable of the highly efficient expression of one or more foreign proteins and are suitable for use as a vaccine for generating a protective immune response against pathogens. The invention provides in particular K. lactis strains for the targeted cloning of foreign antigen-coding nucleic acids into the yeast genome of the K. lactis strain, which is characterized in that the K. lactis strain has integrated expression cassettes for foreign antigens as an alternative or in addition to the KILAC4 locus on the KIURA3-20 locus (KLLA0E22771g) and/or on the KIMET5-1 locus (KLLA0B03938g). The invention further relates to integrative expression vectors and to methods for producing the K. lactis strains of the invention as well as to the use thereof as vaccines.

The present invention relates to a recombinant avian herpes virus, which comprises at least two recombinant nucleotide sequences, each recombinant nucleotide sequence encoding a distinct antigenic peptide, wherein the at least two recombinant nucleotide sequences are inserted into distinct non-coding regions of the viral genome chosen among the region located between UL44 and UL45, the region located between UL45 and UL46, the region located between US10 and SORF3, and the region located between SORF3 and US2.

The present invention regards recombinant HVT (rHVT) constructs, useful as multivalent vector vaccine for poultry. The rHVT comprise 4 heterologous genes from poultry pathogens: the VP2 gene from IBDV, the F gene from NDV, and the gD and gI genes from ILTV. The VP2 and F genes are inserted in the Us genome region of the rHVT. The gD-gI genes are inserted in the UL genome region, either between UL44 and UL45, or between UL45 and UL46. The rHVTs proved to be genetically stable in vitro and in vivo, and expressed all inserted genes well enough to induce protective immunity in vaccinated poultry against IBDV, NDV, and ILTV.

The invention relates to recombinant Kluyveromyces lactis (K. lactis) yeasts which are capable of the highly efficient expression of one or more foreign proteins and are suitable for use as a vaccine for generating a protective immune response against pathogens. The invention provides in particular K. lactis strains for the targeted cloning of foreign antigen-coding nucleic acids into the yeast genome of the K. lactis strain, which is characterized in that the K. lactis strain has integrated expression cassettes for foreign antigens as an alternative or in addition to the KILAC4 locus on the KIURA3-20 locus (KLLA0E22771g) and/or on the KIMET5-1 locus (KLLA0B03938g). The invention further relates to integrative expression vectors and to methods for producing the K. lactis strains of the invention as well as to the use thereof as vaccines.

The present invention relates to a recombinant avian herpes virus, which comprises at least two recombinant nucleotide sequences, each recombinant nucleotide sequence encoding a distinct antigenic peptide, wherein the at least two recombinant nucleotide sequences are inserted into distinct non-coding regions of the viral genome chosen among the region located between UL44 and UL45, the region located between UL45 and UL46, the region located between US10 and SORF3, and the region located between SORF3 and US2.

The present invention discloses novel recombinant multivalent non-pathogenic Marek's Disease virus constructs that encode and express both Infectious Laryngotracheitis Virus protein antigens and an Infectious Bursal Disease virus protein antigen, and methods of their use in poultry vaccines.

Methods of producing, propagating and multiplying viruses, methods of identifying the presence of a virus in a sample, specifically methods using Japanese eel cell cultures. Also provided are an isolated Japanese eel cell culture, optionally infected with a virus, vaccines comprising viruses grown according to the methods of the invention, and a kit for propagating viruses comprising the Japanese eel cell culture. The virus may be a fish virus such as nodavirus, Infectious Pancreatic Necrosis Virus (IPNV) and Salmon Pancreas Disease Virus (SPDV).

The present invention provides recombinant herpesvirus of turkeys (HVT) vectors that contain and express antigens of avian pathogens, compositions comprising the recombinant HVT vectors and polyvalent vaccines comprising the recombinant HVT vectors. The present invention further provides methods of vaccination against a variety of avian pathogens and method of producing the recombinant HVT vectors.

Poultry vaccines against infectious bronchitis and Turkey Rhinotracheitis are provided. The vaccines are adjuvanted with oil emulsion containing an immunostimulatory oligonucleotide. The methods of using the vaccines are also provided.

Disclosed are compositions, kits, and methods for enhancing growth in an animal in need thereof. The methods typically comprise administering orally to the animal a composition comprising biodegradable particles, the biodegradable particles comprising a polymer or a co-polymer comprising polymerized lactic acid and having an effective average diameter of 0.5-5 m. In the methods, the animal is administered a dose of the biodegradable particles that is effective for improving feed conversion rate in the animal in comparison to an animal that is not administered the composition.