Spronken, M.I.

virus fluenza fluenza virus vaccine influenza sequence 293 t cells polymerase mdck cells plasmid strain titer segment virus titers system subtype embryonated chicken eggs antigenic gene segments transfection method nucleotide production /mallard event influenza virus reassortment events h 3n viruses evolution reassortment substitution model infection fluenza viruses expression virus production transfected reverse-genetic antibody protein genetic table study netherland qt 6 cells virol experiment /netherland preparation giraf vector neuraminidase residue g residues chicken encoding challenge h 3n virus replication outbreak virology group animal rescue vaccination position culture research supernatant vaccinated medium promoter titre minigenome 37 ◦ c distance ml trees virus titres smith analysis