Neurology
April 21, 2016
Association Between Influenza Vaccination and Development of Guillain-Barré Syndrome in Adults: A Vaccine Safety Datalink (VSD) and Vaccine Adverse Event Reporting System (VAERS) Study (S53.007)
Francisco Gomez2, Mohammad El-Ghanem4, Abu Nasar1 and Nizar Souayah3
Abstract
Objective: To investigate whether there is correlation between Guillain-Barré Syndrome (GBS) and influenza vaccination in adults, utilizing Vaccine Adverse Event Reporting System (VAERS), and vaccine safety datalink (VSD) databases Background: There are reports of GBS after influenza vaccination, efforts have been undertaken to find a link between the two Methods: Data from VAERS and VSD were used during 1991-2000 time period. Two approaches utilized: self-controlled case series and case-centered. Six weeks after vaccination was defined as the risk period of possible cause effect between vaccination and GBS. Results: There were 69 VSD and 62 VAERS GBS cases after vaccination. VSD mean age was 65.9±12.07 and VAERS 55.83±15.4 years. Male distribution in VSD and VAERS was 64[percnt] and 53[percnt] respectively (p0.221) The incidence of GBS after vaccination in the VSD population was 2/100,000 Using case centered analysis, there was no significant difference between the risk and control periods in the VSD database ( 10[percnt] vs 8.5[percnt] p0.771). Similar results were observed with self-controlled case design. However in VAERS most cases were reported within the risk period. (96.5[percnt] vs 3.5[percnt] p< 0.001). Conclusions: There was no significant increase in incidence of GBS after influenza vaccination in the risk period compared to the control period or the general population in the VSD database. There is a significant difference in the distribution of GBS cases between VSD and VAERS. Several factors may explain this discrepancy: VSD is an active surveillance system whereas VAERS is a passive surveillance system, case ascertainment was different between databases and no case in VAERS fulfilled Brighton criteria, all VSD, but not VAERS patients belong to one health care system, and acute event close to the vaccination date are more reported than events occurring late after vaccination.