Influenza virus reassortment

Abstract

New influenza donor strains for the production of reassortant influenza A viruses are provided.

1 - 32 . (canceled) 
     
     
         33 . A non-naturally occurring reassortant influenza A virus comprising six backbone viral segments, a hemagglutinin (HA) segment, and a neuraminidase (NA) segment, wherein the reassortant influenza A virus comprises PB1 and PB2 viral segments from a same donor strain and (1) the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 80% identity to SEQ ID NO: 18 and (2) the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 80% identity to SEQ ID NO: 19. 
     
     
         34 . The reassortant influenza A virus of  claim 33 , wherein the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 90% identity to SEQ ID NO: 18. 
     
     
         35 . The reassortant influenza A virus of  claim 33 , wherein the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 99% identity to SEQ ID NO: 18. 
     
     
         36 . The reassortant influenza A virus of  claim 33 , wherein the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 90% identity to SEQ ID NO: 19. 
     
     
         37 . The reassortant influenza A virus of  claim 33 , wherein the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 99% identity to SEQ ID NO: 19. 
     
     
         38 . The reassortant influenza A virus of  claim 33 , wherein the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 90% identity to SEQ ID NO: 18 and the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 90% identity to SEQ ID NO: 19. 
     
     
         39 . The reassortant influenza A virus of  claim 33 , wherein the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 99% identity to SEQ ID NO: 18 and the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 99% identity to SEQ ID NO: 19. 
     
     
         40 . A method of preparing a non-naturally occurring reassortant influenza A virus comprising:
 (1) introducing into a culture host expression constructs which encode six backbone viral segment, a hemagglutinin (HA) segment and a neuraminidase (NA) segment, wherein two of the constructs encode PB1 and PB2 viral segments from a same donor strain and (1) the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 80% identity to SEQ ID NO: 18 and (2) the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 80% identity to SEQ ID NO: 19; and   (2) culturing the culture host in order to produce the reassortant virus.   
     
     
         41 . The method of  claim 40 , further comprising purifying the reassortant virus. 
     
     
         42 . The method of  claim 40 , wherein the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 90% identity to SEQ ID NO: 18. 
     
     
         43 . The method of  claim 40 , wherein the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 99% identity to SEQ ID NO: 18. 
     
     
         44 . The method of  claim 40 , wherein the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 90% identity to SEQ ID NO: 19. 
     
     
         45 . The method of  claim 40 , wherein the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 99% identity to SEQ ID NO: 19. 
     
     
         46 . The method of  claim 40 , wherein the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 90% identity to SEQ ID NO: 18 and the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 90% identity to SEQ ID NO: 19. 
     
     
         47 . The method of  claim 40 , wherein the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 99% identity to SEQ ID NO: 18 and the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 99% identity to SEQ ID NO: 19. 
     
     
         48 . A method of preparing a vaccine comprising:
 (1) infecting a culture host with a reassortant influenza A virus comprising six backbone viral segments, a hemagglutinin (HA) segment and a neuraminidase (NA) segment, wherein the reassortant influenza A virus comprises PB1 and PB2 viral segments from a same donor strain and (1) the PB1 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 80% identity to SEQ ID NO: 18 and (2) the PB2 viral segment comprises a nucleotide sequence that encodes a viral polypeptide with at least 80% identity to SEQ ID NO: 19;   (2) culturing the host to produce the virus;   (3) purifying the virus; and   (4) preparing a vaccine from the virus.   
     
     
         49 . The method of  claim 48 , wherein the culture host is an embryonated hen egg or a eukaryotic cell. 
     
     
         50 . The method of  claim 49 , wherein the culture host is a eukaryotic cell and the eukaryotic cell is MDCK, Vero, or PerC6 cell. 
     
     
         51 . The method of  claim 48 , wherein the virus is inactivated. 
     
     
         52 . The method of  claim 48 , wherein the vaccine is a whole virion vaccine, a split virion vaccine, a surface antigen vaccine, or a virosomal vaccine.