title: Improving the representativeness of influenza viruses shared within the WHO Global Influenza Surveillance and Response System.
abstract: BACKGROUND
  Sharing influenza viruses within the WHO Global Influenza Surveillance and Response System is crucial for monitoring evolution of influenza viruses.
  
  
  OBJECTIVE
  Analysis of timeliness and geographic representativeness of viruses shared by National Influenza Centres (NICs) in the WHO European Region with the London WHO Collaborating Centre for Reference and Research on Influenza for the Northern Hemisphere's 2010-2011 and 2011-2012 influenza seasons.
  
  
  METHODS
  Data from NICs on influenza-positive specimens shared with WHO CC London for the above-mentioned influenza seasons were analyzed for timeliness of sharing with respect to the February deadline (31 January) for inclusion in the WHO consultations on the composition of influenza virus vaccines for the Northern Hemisphere and geographic representativeness.
  
  
  RESULTS
  The 2010-2011 and 2011-2012 seasons were different in terms of the seasonal pattern, the timing of the epidemic, and the dominant virus. Consistent patterns of virus sharing across the seasons were observed. Approximately half the viruses collected before the deadline were not shared within the deadline; the average delay between date of specimen collection and shipment receipt was 3 and 1·5 months for the first and second season, respectively.
  
  
  CONCLUSIONS
  A baseline was provided for future work on enhancement of specimen sharing in the WHO European Region and improving the vaccine virus selection process. Greater insight into virus selection criteria applied by countries and the causes of delays in shipment are needed to understand the representativeness of viruses shared and to assess the importance of this for vaccine strain selection.
authors.affiliation: Division of Communicable Diseases, Health Security & Environment, WHO Regional Office for Europe, Copenhagen Ø, Denmark.
authors.forename: Dmitriy
authors.initials: D
authors.lastname: Pereyaslov
authors.affiliation: Division of Communicable Diseases, Health Security & Environment, WHO Regional Office for Europe, Copenhagen Ø, Denmark.
authors.forename: Galina
authors.initials: G
authors.lastname: Zemtsova
authors.affiliation: Division of Communicable Diseases, Health Security & Environment, WHO Regional Office for Europe, Copenhagen Ø, Denmark.
authors.forename: Christine
authors.initials: C
authors.lastname: Gruessner
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, The Francis Crick Institute, Mill Hill Laboratory, London, UK.
authors.forename: Rodney S
authors.initials: RS
authors.lastname: Daniels
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, The Francis Crick Institute, Mill Hill Laboratory, London, UK.
authors.forename: John W
authors.initials: JW
authors.lastname: McCauley
authors.affiliation: Division of Communicable Diseases, Health Security & Environment, WHO Regional Office for Europe, Copenhagen Ø, Denmark.
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Brown
mesh_terms: D003299:Cooperative Behavior; D005060:Europe / Q000453:epidemiology; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification; D053122:Influenza A Virus, H3N2 Subtype / Q000302:isolation & purification; D009981:Influenza B virus / Q000302:isolation & purification; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D008131:London; D009975:Orthomyxoviridae / Q000145:classification / Q000302:isolation & purification; D011159:Population Surveillance; D012621:Seasons; D014944:World Health Organization
chemical_list: D007252:Influenza Vaccines
keywords: Influenza vaccine virus selection; WHO recommendations; influenza vaccine viruses