Eight-plasmid system for rapid generation of influenza virus vaccines

Vaccine. 2002 Aug 19;20(25-26):3165-70. doi: 10.1016/s0264-410x(02)00268-2.


The antigenic variation of influenza A virus hemagglutinin (HA) and neuraminidase (NA) glycoproteins requires frequent changes in vaccine formulation. The classical method of creating influenza virus seed strains for vaccine production is to generate 6 + 2 reassortants that contain six genes from a high-yield virus, such as A/PR/8/34 (H1N1) and the HA and NA genes of the circulating strains. The techniques currently used are time-consuming because of the selection process required to isolate the reassortant virus. We generated the high-yield virus A/PR/8/34 (H1N1) entirely from eight plasmids. Its growth phenotype in embryonated chicken eggs was equivalent to that of the wild-type virus. By using this DNA-based cotransfection technique, we generated 6 + 2 reassortants that had the antigenic determinants of the influenza virus strains A/New Caledonia/20/99 (H1N1), A/Panama/2007/99 (H3N2), A/teal/HK/W312 (H6N1), and A/quail/HK/G1/97 (H9N2). Our findings demonstrate that the eight-plasmid system allows the rapid and reproducible generation of reassortant influenza A viruses for use in the manufacture of vaccines.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigenic Variation / genetics
  • Birds / virology
  • Cell Line
  • Chick Embryo
  • China
  • Czechoslovakia
  • DNA, Recombinant / genetics
  • Dogs
  • Genes, Viral
  • Genetic Vectors / genetics*
  • Influenza A virus / genetics*
  • Influenza A virus / immunology
  • Influenza A virus / isolation & purification
  • Influenza Vaccines / biosynthesis*
  • Influenza Vaccines / genetics
  • Influenza Vaccines / immunology
  • Influenza Vaccines / isolation & purification
  • New Caledonia
  • Panama
  • Phenotype
  • Reassortant Viruses / genetics*
  • Reassortant Viruses / immunology
  • Reassortant Viruses / isolation & purification
  • Reproducibility of Results
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transfection
  • Virus Cultivation


  • DNA, Recombinant
  • Influenza Vaccines