Herpesvirus of turkeys vectored vaccine against avian influenza in poultry
The present application applies to the field of veterinary vaccines, in particular of vaccines for poultry against avian influenza. The vaccine is based on a recombinant viral vector expressing the haemagglutinin protein of an influenza virus, wherein the vector is herpes virus of turkeys (HVT) and the haemagglutinin gene is driven by a glycoprotein B gene promoter from a mammalian herpesvirus. A vaccine comprising this HVT+HA vector can be used to induce a protective immune response against avian influenza in poultry, and to reduce the spread of AIV. The invention also relates to methods, uses, and vaccines involving the HVT+HA vector.
1. A recombinant herpes virus of turkeys (HVT) vector comprising a heterologous nucleic acid, wherein said heterologous nucleic acid comprises an extended mammalian herpesvirus glycoprotein B (gB) gene promoter operably linked to a nucleotide sequence which encodes an influenza virus (IV) hemagglutinin (HA) protein, wherein the extended mammalian herpesvirus gB gene promoter comprises the nucleotide sequence as in SEQ ID NO: 2.
2. The recombinant HVT vector according to claim 1 , wherein the nucleotide sequence encoding an IV HA protein is derived from an avian IV (AIV).
3. The recombinant HVT vector according to claim 2 , wherein the nucleotide sequence encoding the AIV HA protein, encodes an AIV HA protein that has at least 90% amino acid sequence identity to the amino acid sequence as in SEQ ID NO: 4 or 6.
4. The recombinant HVT vector according to claim 2 , wherein the nucleotide sequence encoding the AIV HA protein has a nucleotide sequence that has at least 90% nucleotide sequence identity to the nucleotide sequence as in SEQ ID NO: 3 or 5.
5. A method for the preparation of the recombinant HVT vector according to claim 1 , comprising the integration of a heterologous nucleic acid into the genome of an HVT, wherein said heterologous nucleic acid comprises an extended mammalian herpesvirus glycoprotein B (gB) gene promoter operably linked to a nucleotide sequence which encodes an influenza virus (IV) hemagglutinin (HA) protein, wherein the extended mammalian herpesvirus gB gene promoter comprises the nucleotide sequence of SEQ ID NO: 2.
6. An immunogenic composition, comprising the recombinant HVT vector according to claim 1 , and a pharmaceutically acceptable carrier.
7. The immunogenic composition according to claim 6 , wherein the immunogenic composition can be applied in ovo.
8. A method for the preparation of the immunogenic composition according to claim 6 , said method comprising admixing the recombinant HVT vector according to claim 1 with a pharmaceutically acceptable carrier.
9. A method of inducing an immune response in poultry against avian influenza, comprising the step of inoculating said poultry with the immunogenic composition according to claim 6 .