Multivalent HVT vector vaccine
The present invention describes a recombinant herpesvirus of turkeys (rHVT) that can be used as a vector vaccine for poultry against infection and disease from multiple poultry pathogens. Specifically the rHVT expresses an infectious bursal disease virus (IBDV) viral protein 2 (VP2) gene and a Newcastle disease virus (NDV) fusion (F) protein gene from a first and a second expression cassette inserted in the unique small (Us) region, and expresses an avian influenza vims (AIV) haemagglutinin (HA) gene from a third expression cassette inserted in the unique long (UL) region of the genome of said rHVT either between the UL40 and UL41 genes, or between the UL44 and UL45 genes. This rHVT can be used to vaccinate poultry against MDV, IBDV, NDV and AIV.
1 . A recombinant herpesvirus of turkeys (rHVT) expressing an infectious bursal disease virus (IBDV) viral protein 2 (VP2) gene and a Newcastle disease virus (NDV) fusion (F) protein gene from a first and a second expression cassette which are inserted in the unique small (Us) region of the genome of said rHVT, wherein the rHVT also expresses an avian influenza virus (AIV) haemagglutinin (HA) gene from a third expression cassette which is inserted in the unique long (UL) region of the genome of said rHVT either between the UL40 and UL41 genes, or between the UL44 and UL45 genes.
2 . The rHVT of claim 1 , wherein the IBDV VP2 gene is present in the first expression cassette comprising in 5′ to 3′ direction and in the order of:
a. a murine cytomegalovirus immediate early 1 gene (mCMV-IE1) promoter,
b. an IBDV VP2 gene, and
c. a transcription terminator,
and whereby the promoter and the terminator of said expression cassette are operatively linked to the VP2 gene.
3 . The rHVT of claim 1 , wherein the NDV F protein gene is present in the second expression cassette comprising in 5′ to 3′ direction and the order of:
a. a human cytomegalovirus immediate early 1 gene (hCMV-IE1) promoter,
b. an NDV F protein gene, and
c. a transcription terminator,
and whereby the promoter and the terminator of said expression cassette are operatively linked to the F gene.
4 . The rHVT of claim 1 , wherein the first and the second expression cassette are inserted in the same locus or in different loci of the Us region of the genome of said rHVT.
5 . The rHVT of claim 1 , wherein the first and the second expression cassette are both inserted in the Us2 gene, or are both inserted in the Us10 gene, or one is inserted in the Us2 gene and the other is inserted in the Us10 gene.
6 . The rHVT of claim 1 , wherein the first and the second expression cassette are combined into a single expression cassette.
7 . The rHVT of claim 6 , wherein the combined single expression cassette is inserted in the Us2 gene.
8 . The rHVT of claim 1 , wherein the AIV HA gene is present in the third expression cassette comprising, in 5′ to 3′ direction and in the order of:
a. a glycoprotein B (gB) gene promoter from a mammalian herpesvirus,
b. an AIV HA protein gene, and
c. a transcription terminator,
and whereby the promoter and the terminator of said expression cassette are operatively linked to the HA gene.
9 . The rHVT of claim 1 , wherein the AIV HA protein gene encodes an HA protein of a serotype selected from the group consisting of H5, H7 and H9.
10 . A host cell comprising the rHVT of claim 1 .
11 . A vaccine for poultry comprising the rHVT of claim 1 , and a pharmaceutically acceptable carrier.
12 . The vaccine of claim 11 , further comprising at least one additional immunoactive component.
13 . A method of preparing a vaccine for poultry comprising the steps of:
a. infecting host cells in vitro with the rHVT of claim 1 ,
b. harvesting the infected host cells, and
c. admixing the harvested infected host cells with a pharmaceutically acceptable carrier.
14 . A method of preventing or reducing infection by MDV, IBDV NDV and/or AIV, or their associated signs of disease in poultry, comprising administering the vaccine of claim 12 to the poultry.
15 . A vaccine for poultry comprising the host cell of claim 10 , and a pharmaceutically acceptable carrier.
16 . A method of vaccinating poultry to prevent or reduce infection by MDV, IBDV NDV and/or AIV, or their associated signs of disease, comprising the step of inoculating said poultry with the vaccine of claim 15 .
17 . The rHVT of claim 8 , wherein the AIV HA gene encodes an HA protein of a serotype selected from the group consisting of H5, H7 and H9.
18 . The rHVT of claim 17 , wherein the NDV F protein gene is present in the second expression cassette comprising in 5′ to 3′ direction and in the order of:
a. a human cytomegalovirus immediate early 1 gene (hCMV-IE1) promoter,
b. an NDV F protein gene, and
c. a transcription terminator,
and whereby the promoter and the terminator of said expression cassette are operatively linked to the F gene.
19 . The rHVT of claim 18 , wherein the IBDV VP2 gene is present in the first expression cassette comprising in 5′ to 3′ direction and in this order:
a. a murine cytomegalovirus immediate early 1 gene (mCMV-IE1) promoter,
b. an IBDV VP2 gene, and
c. a transcription terminator,
and whereby the promoter and the terminator of said expression cassette are operatively linked to the VP2 gene.
20 . A method of vaccinating poultry to prevent or reduce infection by MDV, IBDV NDV and/or AIV, or their associated signs of disease, comprising the step of inoculating said poultry with the vaccine of claim 19 .