title: Simulation study of the effect of influenza and influenza vaccination on risk of acquiring Guillain-Barré syndrome.
abstract: It is unclear whether seasonal influenza vaccination results in a net increase or decrease in the risk for Guillain-Barré syndrome (GBS). To assess the effect of seasonal influenza vaccination on the absolute risk of acquiring GBS, we used simulation models and published estimates of age- and sex-specific risks for GBS, influenza incidence, and vaccine effectiveness. For a hypothetical 45-year-old woman and 75-year-old man, excess GBS risk for influenza vaccination versus no vaccination was -0.36/1 million vaccinations (95% credible interval -1.22% to 0.28) and -0.42/1 million vaccinations (95% credible interval, -3.68 to 2.44), respectively. These numbers represent a small absolute reduction in GBS risk with vaccination. Under typical conditions (e.g. influenza incidence rates >5% and vaccine effectiveness >60%), vaccination reduced GBS risk. These findings should strengthen confidence in the safety of influenza vaccine and allow health professionals to better put GBS risk in context when discussing influenza vaccination with patients.
authors.forename: Steven
authors.initials: S
authors.lastname: Hawken
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Kwong
authors.forename: Shelley L
authors.initials: SL
authors.lastname: Deeks
authors.forename: Natasha S
authors.initials: NS
authors.lastname: Crowcroft
authors.forename: Allison J
authors.initials: AJ
authors.lastname: McGeer
authors.forename: Robin
authors.initials: R
authors.lastname: Ducharme
authors.forename: Michael A
authors.initials: MA
authors.lastname: Campitelli
authors.forename: Doug
authors.initials: D
authors.lastname: Coyle
authors.forename: Kumanan
authors.initials: K
authors.lastname: Wilson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003198:Computer Simulation; D005260:Female; D020275:Guillain-Barre Syndrome / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D007252:Influenza Vaccines / Q000009:adverse effects*; D007251:Influenza, Human / Q000150:complications* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D012306:Risk; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines