Turkey herpesvirus vectored recombinant containing avian influenza genes

Abstract

The present invention provides a recombinant turkey herpesvirus modified by the presence of the cDNA encoding the hemagglutinin protein of avian influenza virus under a promoter. A poultry vaccine comprising the recombinant turkey herpesvirus described in the present invention can induce serological responses that may be easily detected by the hemagglutination inhibition assay but not by commercially available diagnostic ELISA kits; thus enabling easy differentiation between vaccination and field infection.

1 . A recombinant turkey herpesvirus comprising a hemagglutinin gene of avian influenza virus and the cytomegalovirus immediate early promoter, wherein said hemagglutinin gene is under control of said promoter. 
     
     
         2 . A recombinant turkey herpesvirus as in  claim 1 , wherein said hemagglutinin gene and said promoter are present in a non-essential region of the turkey herpesvirus genome. 
     
     
         3 . A recombinant turkey herpesvirus as in  claim 2 , wherein said non-essential region is between UL45 and UL46 of the turkey herpesvirus genome. 
     
     
         4 . A recombinant turkey herpesvirus as in  claim 1 , wherein said avian influenza virus is H5 subtype. 
     
     
         5 . A recombinant turkey herpesvirus as in  claim 1 , wherein said avian influenza virus is A/Turkey/Wisconsin/68 (H5N9) strain. 
     
     
         6 . A recombinant turkey herpesvirus as in  claim 1 , wherein a nucleotide sequence of said hemagglutinin gene is shown in SEQ ID NO: 1. 
     
     
         7 . A poultry vaccine comprising a recombinant turkey herpesvirus as in  claim 1 . 
     
     
         8 . A poultry vaccine comprising a recombinant turkey herpesvirus as in  claim 1  wherein said vaccine confers hemagglutination inhibition titers of more than 50 (geometric mean titer) by five weeks post vaccination in vaccinated chickens, wherein said hemagglutination inhibition titers are defined as the highest dilutions of sera exhibiting inhibition of hemagglutination when using four hemagglutination units of an inactivated avian influenza virus homologous antigen. 
     
     
         9 . A method of conferring high hemagglutination inhibition titers by inoculating chickens with a recombinant turkey herpesvirus as in  claim 1 . 
     
     
         10 . A method as in  claim 9 , wherein said inoculated chickens develop hemagglutination inhibition titers of more than 50 (geometric mean titer) by five weeks post vaccination, wherein said hemagglutination inhibition titers are defined as the highest dilutions of sera exhibiting inhibition of hemagglutination when using four hemagglutination units of an inactivated avian influenza virus homologous antigen.