Risk of Confirmed Guillain-Barre Syndrome Following Receipt of Monovalent Inactivated Influenza A (H1N1) and Seasonal Influenza Vaccines in the Vaccine Safety Datalink Project, 2009-2010.
American Journal of Epidemiology, 2012
Abstract An increased risk of Guillain-BarrÃ© syndrome (GBS) following administration of the 1976 swine influenza vaccine led to a heightened focus on GBS when monovalent vaccines against a novel influenza A (H1N1) virus of swine origin were introduced in 2009.
GBS cases following receipt of monovalent inactivated (MIV) and seasonal trivalent inactivated (TIV) influenza vaccines in the Vaccine Safety Datalink Project in 2009-2010 were identified in electronic data and confirmed by medical record review.
Within 1-42 days following vaccination, 9 cases were confirmed in MIV recipients (1.48 million doses), and 8 cases were confirmed in TIV-only recipients who did not also receive MIV during 2009-2010 (1.72 million doses).
Five cases following MIV and 1 case following TIV-only had an antecedent respiratory infection, a known GBS risk factor; furthermore, unlike TIV, MIV administration was concurrent with heightened influenza activity.
In a self-controlled risk interval analysis comparing GBS onset within 1-42 days following MIV with GBS onset 43-127 days following MIV, the risk difference was 5.0 cases per million doses (95% confidence interval: 0.5, 9.5).
No statistically significant increased GBS risk was found within 1-42 days following TIV-only vaccination versus 43-84 days following vaccination (risk difference = 1.1 cases per million doses, 95% confidence interval: -3.1, 5.4).
Further evaluation to assess GBS risk following both vaccination and respiratory infection is warranted.
PMID: 22582210 [PubMed - as supplied by publisher] Full Text Sources
Preliminary results: surveillance for Guillain-BarrÃ© syndrome after receipt of influenza A (H1N1) 2009 monovalent vaccine - United States, 2009-2010.
The risk of Guillain-BarrÃ© syndrome associated with influenza A (H1N1) 2009 monovalent vaccine and 2009-2010 seasonal influenza vaccines: results from self-controlled analyses.