A cell contacted with a plurality of orthomyxovirus vectors, comprising: (i) a vector comprising a promoter operably linked to a influenza cDNA cDNA linked to a transcription termination sequence, ( ii) a vector comprising a promoter operatively linked to an influenza virus PB1 cDNA linked to a transcription termination sequence, (iii) a vector comprising a promoter operably linked to a PB2 cDNA of the influenza virus linked to a transcription termination sequence, (iv) a vector comprising a promoter operably linked to an HA cDNA of the influenza virus linked to a transcription termination sequence, (v ) a vector comprising a promoter operatively linked to an influenza cDNA cDNA linked to a transcription termination sequence, (vi) a vector comprising a promoter operably linked to a cDNA of NA d influenza virus linked to a transcription termination sequence, (vii) a vector comprising a promoter operably linked to an M cDNA of influenza virus linked to a transcription termination sequence, (viii ) a vector comprising a promoter operatively linked to an influenza cDNA NS linked to a transcription termination sequence, (ix) a vector comprising a promoter operably linked to a DNA segment that encodes a influenza PA polypeptide and linked to a transcription termination sequence, (x) a vector comprising a promoter operably linked to a segment of DNA encoding a flu PB1 polypeptide and linked to a sequence of termination of transcription, (xi) a vector comprising a promoter operably linked to a segment of DNA encoding a flu PB2 polypeptide and linked to a transcription termination sequence, and (xii) or A vector comprising a promoter operatively linked to a segment of DNA encoding an influenza NP polypeptide and linked to a transcription termination sequence wherein said cell expresses said orthomyxovirus.Una célula puesta en contacto con una pluralidad de vectores del ortomixovirus, que comprende: (i) un vector que comprende un promotor unido de forma operativa a un ADNc de
