Table 4. Summary of association of GBS to influenza vaccines in peer-reviewed literature.

Author	Title	Publication year	Type(s) of Influenza vaccine(s) studied	DB used	Method	Conclusion
Baxter, R. [43]	Recurrent Guillain-Barre Syndrome Following Vaccination	2012	TIV	Kaiser Permanente Northern California	review of medical records of GBS confirmed cases	low risk of recurrent GBS
Lee, S.J. [44]	Neurologic adverse events following influenza A (H1N1) vaccinations in children	2012	H1N1 MIV	N/A	single case study of 14 cases Nov.09–Mar.10	No major Neurologic AEs
Andrews, N. [45]	Guillain-Barre syndrome and H1N1 (2009) pandemic influenza vaccination using an AS03 adjuvanted vaccine in the United Kingdom: Self-controlled case series	2011	H1N1 MIV (2009)	N/A	review of patient records of post-vaccination GBS cases using self-controlled case series method on case identified in hospital episode statistics	no evidence of increased risk of GBS 6 weeks after vaccination
Cheo, Y.J. [36]	Serious adverse events follwing receipt of trivalent inactivated influenza vaccine in Korea 2003–2010	2011	TIV	Korea National Vaccine Injury Compensation Program (2003–2010)	retrospective review of clinical records, case investigation reports, conference materials and billing records.	GBS was the most-common SAEs reported after TIV immunization
Dieleman, J. [46]	Guillain-Barre syndrome and adjuvanted pandemic influenza A (H1H1) 2009 vaccine: multinational case-control study in Europe	2011	H1N1 MIV (2009)	N/A	GBS and Fisher syndrome case-control study (matched on age, sex, index date, and country)	no increased risk of GBS
Lee. G.M. [22]	H1N1 and Seasonal Influenza Vaccine Safety in the Vaccine Safety Datalink Project	2011	H1N1 MIV, LAMV, TIV, LAIV	Vaccine Safety Datalink	Nov'09–Apr'10 weekly signal detection analysis using self-controlled design /or/ current-vs-historical comparison	No association of GBS and other neurologic outcomes. For MIV - signal of Bell's Palsy. Higher reports of GBS in TIV than LAIV.
Sejvar, J.J. [47]	Guillain-Barre Syndrome Following Influenza Vaccination: Causal or Coincidental?	2011	MIV, TIV	N/A	analysis of past studies	question not answered, causality of GBS with regards to influenza vaccination remained inconclusive
Verity, C. [48]	Guillain-Barre syndrome and H1N1 influenza vaccine in UK children	2011	H1N1 MIV (?)	N/A	Sep'09–Aug'10 follow-up clinical questionairs	no association of GBS to influenza vaccination
Williams, S. E. [49]	Causality assessment of serious neurologic adverse events following 2009 H1N1 vaccination	2011	H1N1 MIV (2009)	VAERS	review of SAE reports in Oct'09–Mar'10	inconclusive association assessment, investigation of GBS and other SNAEs causality is difficult, VAERS reporting process can be improved
Burwen, D.R. [37]	Evaluation of Guillain-Barre Syndrome among recipients of influenza vaccine in 2000 and 2001	2010	not specified	Medicare claim data & hospital records	Incidence Rate Ratio	slightly non-significant elevated incidence rate ratio of GBS for all seasons combined
McNeil, M.M. [50]	A cluster of nonspecific adverse events in a military reserve unit following pandemic influenza A (H1N1) 2009 vaccination-Possible stimulate reporting?	2010	H1N1 MIV	VAERS	surey & review of index cases' VAERS reports, hospital records, vaccination status, aiagnostic results and outcome in comparison to VAERS reports of the same screen lot	GBS in the index case not confirmed, possbile stimulated reporting among reporters from the index case's cohort
Vellozzi, C. [51]	Adverse events following infuenza A (H1N1) 2009 monovalent vaccines reported to the Vaccine Adverse Event Reporting System, United States, October 1, 2009–January 31, 2010	2010	H1N1 MIV	VAERS	empirical Bayesian data mining and reporting proportions with clinical review of reports	death, GBS, and anaphylaxis were rare (<2 per million doses from ∼10,000 VEARS reports)
Evans, D. [52]	“Prepandemic” Immunization for Novel Influenza Viruses, “Swine Flu” Vaccine, Guillain-Barre Syndrome, and the Detection of Rare Severe Adverse Events	2009	clinical trials of H5N1	N/A	review of past pandemic influenza studies	GBS association with Influenza vaccination remained inconclusive. Possible mechanism of GBS association with influenza vaccine was discussed.
Vellozzi, C. [38]	Safety of trivalent inactivated influenza vaccines in adults: Background for pandemic influenza vaccine safety monitoring	2009	TIV (1990–2005)	VAERS	PRR, review of reports of recurrent events and death	slightly elevated risk of SAEs, GBS - most frequently reported SAE, GBS requires continued monitoring
Juurlink, D.N. [39]	Guillain-Barre Syndrome after influenza vaccination in adults: a population-based study	2006	not specified	N/A	self-matched case-series method and time-series analysis	Influenza vaccination is associated with increased risk of hospitalization due to GBS
Izurieta, H.S. [53]	Adverse Events Reported Following Live Cold-Adapted, Intranasal Influenza Vaccine	2005	LAIV	VAERS (2003–2005)	report rate per 100,000 vaccinees	No unexpected serious risks, no GBS, may rarely cause anaphylaxis
Kao, C. [54]	Guillain-Barre syndrome coexisting with pericarditis or nephrotic syndrome after influenza vaccination	2004	not specified	N/A	2 individual case studies	pericarditis or onset nephrotic syndrome may coincidoe with GBS development.
Geier, M.R. [40]	Influenza vaccination and Guillain Barre syndrome	2003	not specified 1991–1999	VAERS	stat. analysis with Corel's Quattro Pro	increased risk of acute GBS and severe GBS in comparison to tetanus-diphtheria control group
Lasky, T. [41]	The Guillain-Barre Syndrome and the 1992–1993 and 1993–1994 influenza vaccines	1998	not specified	VAERS	patient survey and review of hospital discharging records based on VAERS reports	elevated relative risk of GBS 6 weeks after vaccination when combined the two reporting years. No increase in the risk when looking at each year individually.

Abbreviations: MIV – Monovalent Inactivated Influenza Vaccine, TIV – Trivalent Inactivated Influenza Vaccine, LAIV – Live Attenuated Influenza Vaccine, VAERS – Vaccince Adverse Event Reporting System.