Mosaic infectious bursal disease virus vaccines

Abstract

The invention relates to Infectious Bursal Disease Virus (“IBDV”) and vaccines therefor. Provided are infectious recombinant Infectious Bursal Disease Virus (“rIBDV”) essentially incapable of growing in a cell that is not derived from a bursa cell, or an infectious rIBDV having retained at least part of the very virulent characteristics of a very virulent Infectious Bursal Disease Virus (“vvIBDV”).

1 . An infectious recombinant Infectious Bursal Disease Virus (rIBDV) essentially incapable of growing in a non-bursa cell or cell derived from a non-bursa cell.  
     
     
         2 . An infectious rIBDV having retained at least part of the very virulent characteristics of a very virulent Infectious Bursal Disease Virus (vvIBDV).  
     
     
         3 . The rIBDV of  claim 1 , wherein the rIBDV has retained at least part of the very virulent characteristics of a very virulent Infectious Bursal Disease Virus (vvIBDV).  
     
     
         4 . The rIBDV of  claim 2 , wherein said rIBDV is essentially incapable of growing in a CEF cell, a VERO cell or a QM5 cell.  
     
     
         5 . The rIBDV of  claim 3 , wherein the rIBDV's VP2 protein sequence has no asparagine at amino acid position 279.  
     
     
         6 . The rIBDV of  claim 5 , wherein the amino acid sequence of protein VP2 has aspartic acid at amino acid position 279.  
     
     
         7 . The rIBDV of  claim 3 , wherein the protein VP2 has no threonine at amino acid position 284.  
     
     
         8 . The rIBDV of  claim 7 , wherein the protein VP2 has alanine at amino acid position 284.  
     
     
         9 . The rIBDV of  claim 8 , wherein the amino acid sequence of protein VP2 comprises a stretch of amino acids from about position 279 to 289 as found in a vvIBDV isolate such as shown in Table 8.  
     
     
         10 . (canceled)  
     
     
         11 . A method for obtaining an infectious recombinant Infectious Bursal Disease Virus (rIBDV) having retained at least part of the very virulent characteristics of a very virulent Infectious Bursal Disease Virus (vvIBDV), said method comprising: 
 transfecting at least one first cell with a nucleic acid comprising an IBDV genome at least partly derived from a vvIBDV;    incubating said at least one first cell in a culture medium;    recovering rIBDV from said at least one transfected first cell or said culture medium; and    propagating said recovered rIBDV in at least one second cell permissive for said vvIBDV.    
     
     
         12 - 22 . (canceled)  
     
     
         23 . An infectious mosaic IBDV (mIBDV) comprising an rIBDV wherein at least one genome segment comprises nucleic acid derived from at least two different Birna virus isolates.  
     
     
         24 . The mIBDV of  claim 23 , wherein at least one of said isolates is a vvIBDV.  
     
     
         25 . The mIBDV of  claim 24 , wherein said mIBDV is unable to be propagated on a vvIBDV non-permissive cell selected from the group consisting of a VERO cell, a QM5 cell, and a CEP cell.  
     
     
         26 . The mIBDV of  claim 25 , wherein said mIBDV is able to be propagated on a vvIBDV permissive cell.  
     
     
         27 . The mIBDV of  claim 26 , wherein at least one of said isolates is a serotype II IBDV.  
     
     
         28 . The mIBDV of  claim 27 , lacking at least one immunodominant epitope specific for a serotype I IBDV.  
     
     
         29 . A vaccine comprising the rIBDV of  claim 2 .  
     
     
         30 . The rIBDV of  claim 8 , wherein the amino acid sequence of protein VP2 at least comprises a stretch of amino acids from about position 229 to 314.