title: Guillain-Barré syndrome following pandemic (H1N1) 2009 influenza A immunisation in Victoria: a self-controlled case series.
abstract: OBJECTIVE
  To determine the relative incidence (RI) of Guillain-Barré syndrome (GBS) in a single Australian state following pandemic (H1N1) 2009 influenza A immunisation (monovalent vaccine or seasonal trivalent influenza vaccine [TIV]) in 2009-2010.
  
  
  METHODS
  Active GBS surveillance (cases assessed by two neurologists according to the Brighton criteria) from 30 September 2009 to 30 September 2010, conducted at 10 hospitals in Victoria, Australia.
  
  
  METHODS
  The RI of GBS in the risk window of 0-42 days after vaccination.
  
  
  RESULTS
  Sixty-six potential GBS cases were identified, with complete data on 50 confirmed cases. The Victorian annual incidence of GBS was 1.7 per 100 000 population. Three cases had received monovalent vaccine and one case had received seasonal TIV within 42 days of symptom onset. The RI of GBS following monovalent vaccination was 3.4 (95% CI, 0.8-15.0). For TIV, there was one case in the risk period (RI, 0.69; 95% CI, 0.08-5.64).
  
  
  CONCLUSIONS
  This is the first published study reviewing GBS after a trivalent and/or monovalent influenza vaccine containing the pandemic (H1N1) 2009 strain, with only a small proportion of GBS cases occurring after influenza immunisation. H1N1-containing vaccines were not statistically associated with GBS, but this study could not exclude smaller increases in the RI. Active surveillance of adverse events following immunisation is required to maintain public and health care professional confidence in mass vaccine implementation programs.
authors.affiliation: Royal Children's Hospital, Melbourne, VIC, Australia. nigel.crawford@rch.org.au.
authors.forename: Nigel W
authors.initials: NW
authors.lastname: Crawford
authors.forename: Allen
authors.initials: A
authors.lastname: Cheng
authors.forename: Nick
authors.initials: N
authors.lastname: Andrews
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Charles
authors.forename: Hazel J
authors.initials: HJ
authors.lastname: Clothier
authors.forename: Bruce
authors.initials: B
authors.lastname: Day
authors.forename: Timothy
authors.initials: T
authors.lastname: Day
authors.forename: Peter
authors.initials: P
authors.lastname: Gates
authors.forename: Richard
authors.initials: R
authors.lastname: Macdonell
authors.forename: Richard
authors.initials: R
authors.lastname: Macdonnell
authors.forename: Les
authors.initials: L
authors.lastname: Roberts
authors.forename: Victoria
authors.initials: V
authors.lastname: Rodriguez-Casero
authors.forename: Tissa
authors.initials: T
authors.lastname: Wijeratne
authors.forename: Lynette
authors.initials: L
authors.lastname: Kiers
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D020275:Guillain-Barre Syndrome / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D053118:Influenza A Virus, H1N1 Subtype; D007252:Influenza Vaccines / Q000009:adverse effects*; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D011159:Population Surveillance; D012107:Research Design; D012306:Risk; D014739:Victoria / Q000453:epidemiology; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines