Gene-Deleted Variant Strain Of Porcine Pseudorabies Virus, Vaccine Composition, Method Of Making The Same And Use Thereof

Abstract

The present invention provides an attenuated strain of porcine pseudorabies virus (PRV), in which said attenuated strain of PRV is a variant strain of PRV with inactivation of gI/gE/11K/28K proteins. In addition, the present invention also provides a vaccine composition comprising the attenuated strain of PRV as an antigen, a preparation method and use thereof. Proved by immunogenicity and pathogenicity testing of the live vaccine, said live PRV vaccine can provide a good protection for pigs with no clinical signs observed, indicating excellent immune protection.

What is claimed is: 
     
         1 . An attenuated strain of porcine pseudorabies virus comprising a first attenuated porcine pseudorabies virus strain, wherein the first attenuated strain of porcine pseudorabies comprises a porcine pseudorabies virus strain with inactivation of gI/gE/11K/28K protein. 
     
     
         2 . The attenuated strain of porcine pseudorabies virus of  claim 1 , wherein the first attenuated porcine pseudorabies virus strain is a variant strain of pseudorabies virus. 
     
     
         3 . The attenuated strain of porcine pseudorabies virus of  claim 1 , wherein a whole ORF is deleted from a gI/gE/11K/28K gene of the first attenuated porcine pseudorabies virus strain. 
     
     
         4 . The attenuated strain of porcine pseudorabies virus of  claim 2 , wherein the variant strain of pseudorabies virus comprises a virus strain in which gE protein has 95% or greater homology with SEQ ID NO. 05. 
     
     
         5 . The attenuated strain of porcine pseudorabies virus of  claim 4 , wherein said variant strain of pseudorabies virus is obtained through isolation, and when infection with said variant strain occurs in pigs previously immunized with a second attenuated gene deleted porcine pseudorabies virus strain, wherein the second attenuated gene deleted porcine pseudorabies virus strain is prepared according to the prior art, the pigs display clinical signs of infection selected from the group consisting of high fever, depression, and partial or complete loss of appetite. 
     
     
         6 . The attenuated strain of porcine pseudorabies virus of  claim 5 , wherein when exposed to said variant strain of pseudorabies virus, pigs previously immunized with the second attenuated porcine pseudorabies virus strain develop a pseudorabies infection, and wherein the second attenuated porcine pseudorabies vaccine is a prior art strain with deletion of one or more of the group consisting of gE, TK and gI genes. 
     
     
         7 . The attenuated strain of  claim 6 , wherein the pseudorabies infection comprises clinical signs of infection selected from the group consisting of depression and loss of appetite among piglets at the age of 9-10 days. 
     
     
         8 . The attenuated strain of porcine pseudorabies virus of  claim 1 , wherein the first porcine pseudorabies virus strain is selected from the group consisting of an HN1201 strain, HN1202 strain, JS-2012 strain, PRV HeN1 strain, NVDC-PRV-BJ strain, NVDCPRV-HEB strain or NVDC-PRV-SD strain, PRV TJ strain, and PRV-ZJ01 strain. 
     
     
         9 . The attenuated strain of porcine pseudorabies virus of  claim 1 , wherein the first attenuated strain of porcine pseudorabies virus strain comprises a gene variation resulting in inactivation of TK protein. 
     
     
         10 . The attenuated strain of porcine pseudorabies virus of  claim 9 , wherein the gene variation comprises a nucleotide sequence located at a site corresponding to a TK gene of the first attenuated porcine pseudorabies virus strain, and wherein the nucleotide sequence encodes for SEQ ID NO. 4. 
     
     
         11 . A vaccine composition, comprising an immunizing amount of an antigen of an attenuated strain of porcine pseudorabies and a carrier, wherein the attenuated strain of porcine pseudorabies comprises a genetic variation resulting in inactivation of gI/gE/11K/28K protein. 
     
     
         12 . The vaccine composition of  claim 11 , wherein the immunizing amount comprises at least 10 6.0 TCID 50 /ml of the attenuated strain of porcine pseudorabies virus. 
     
     
         13 . The vaccine composition of  claim 11 , wherein the antigen comprises a live attenuated strain of porcine pseudorabies virus, and wherein the vaccine composition further comprises a cryoprotectant. 
     
     
         14 . The vaccine composition of  claim 11 , further comprising an inactivated pathogen or antigen. 
     
     
         15 . The vaccine composition of  claim 14 , wherein the inactivated pathogen or antigen is selected from the group consisting classical swine fever virus, antigen of porcine reproductive and respiratory syndrome virus, antigen of porcine circovirus, antigen of haemophilus parasuis, and antigen of mycoplasma. 
     
     
         16 . A method of treating and preventing pseudorabies infection, comprising immunizing a pig with an antigen comprising a porcine pseudorabies virus strain with inactivation of gI/gE/11K/28K protein. 
     
     
         17 . The method of  claim 16 , wherein the porcine pseudorabies virus strain comprises a virus strain in which gE protein has 95% or greater homology with SEQ ID NO. 05.