title: Rapid generation of pandemic influenza virus vaccine candidate strains using synthetic DNA.
abstract: BACKGROUND
  Vaccination is considered the most effective means of reducing influenza burden. The emergence of H5N1 and pandemic spread of novel H1N1/2009 viruses reinforces the need to have strategies in place to rapidly develop seed viruses for vaccine manufacture.
  
  
  METHODS
  Candidate pandemic vaccine strains consisting of the circulating strain haemagglutinin (HA) and neuraminidase (NA) in an A/PR/8/34 backbone were generated using alternative synthetic DNA approaches, including site-directed mutagenesis of DNA encoding related virus strains, and rapid generation of virus using synthetic DNA cloned into plasmid vectors.
  
  
  RESULTS
  Firstly, synthetic A/Bar Headed Goose/Qinghai/1A/2005 (H5N1) virus was generated from an A/Vietnam/1194/2004 template using site-directed mutagenesis. Secondly, A/Whooper Swan/Mongolia/244/2005 (H5N1) and A/California/04/09 (H1N1) viruses were generated using synthetic DNA encoding the viral HA and NA genes. Replication and antigenicity of the synthetic viruses were comparable to that of the corresponding non-synthetic viruses.
  
  
  CONCLUSIONS
  In the event of an influenza pandemic, the use of these approaches may significantly reduce the time required to generate and distribute the vaccine seed virus and vaccine manufacture. These approaches also offer the advantage of not needing to handle wild-type virus, potentially diminishing biocontainment requirements.
authors.affiliation: CSL Ltd, Parkville, Vic., Australia.
authors.forename: Erin E
authors.initials: EE
authors.lastname: Verity
authors.forename: Sarina
authors.initials: S
authors.lastname: Camuglia
authors.forename: Catherine T
authors.initials: CT
authors.lastname: Agius
authors.forename: Chi
authors.initials: C
authors.lastname: Ong
authors.forename: Robert
authors.initials: R
authors.lastname: Shaw
authors.forename: Ian
authors.initials: I
authors.lastname: Barr
authors.forename: Deborah
authors.initials: D
authors.lastname: Middleton
authors.forename: Steven
authors.initials: S
authors.lastname: Rockman
mesh_terms: D000818:Animals; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000276:immunology; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics / Q000276:immunology; D007252:Influenza Vaccines / Q000235:genetics* / Q000276:immunology*; D016297:Mutagenesis, Site-Directed; D009439:Neuraminidase / Q000235:genetics / Q000276:immunology*; D011995:Recombination, Genetic; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D014614:Vaccines, Synthetic; D014764:Viral Proteins; C487630:NA protein, influenza A virus; D009439:Neuraminidase