Table 2:

Summary of the epidemiologic studies on relationship between Influenza vaccine and autoimmune diseases

Type vaccine	Study design	Patients	Findings: primary effect size estimated (95% CI or p value)	Ref
Studies included in the weight of epidemiologic evidence for Influenza Vaccine and Optic Neuritis
Influenza vaccine	Case control study	-108 patients with optic neuritis	OR for optic neuritis onset any time after influenza vaccination: 1.2 (95% CI, 0.6–2.3)	[60]
	Case control study	-1,131 patients with optic neuritis	OR for optic neuritis onset within 18 weeks of influenza vaccination: 1.01 (95% CI, 0.79–1.29)	[61]
		-3,393 controls
Studies included in the weight of epidemiologic evidence for Influenza Vaccine and MS Relapse in Adults
Influenza vaccine	Double-blind, randomized controlled trial	-49 vaccinated	Significant difference in MS relapse within 28 days or 6 months of influenza vaccination	[62]
		-54 received placebo
	Case-crossover controlled study	-643 patients with definite or probable MS diagnoses	RR of MS relapse within 2 months of influenza vaccination: 1.08 (95% CI, 0.37–3.10)	[63]
Studies included in the weight of epidemiologic evidence for Influenza Vaccine and GBS
Influenza Vaccine	Controlled study	-12 vaccinated	RR of GBS onset within 8 weeks of influenza vaccination: 1.4 (95% CI, 0.7–2.1)	[64]
		-393 unvaccinated
	Controlled study	1979–1980 season:	RR of GBS onset within 8 weeks of vaccination during 1979–1980 season: 0.6 (95% CI, 0.45–1.32). RR of GBS onset within 8 weeks of vaccination during 1980–1981 season: 1.4 (95% CI, 0.80–1.76)	[65]
		-7 vaccinated
		-412 unvaccinated
		1980–1981 season:
		-12 vaccinated
		-347 unvaccinated
Influenza vaccine	Self-controlled study	-Three GBS cases in risk period (42 days after vaccine)	Adjusted RR of GBS onset within 42 days of influenza vaccination: 0.99 (95% CI, 0.32–3.12; p = .99)	[66]
		-225 GBS cases in control period
	Self-controlled study	-51 GBS cases in risk period (2-7 weeks after vaccine)	RR of hospitalization for GBS onset during the 2–7 weeks after influenza vaccination: 1.45 (95% CI, 1.05–1.99)	[67]
		-141 GBS cases in control period (26-43 weeks after vaccine)
	Retrospective study	2005–2006: 12 events in risk period; 14.4 events in control period. 2006–2007: 17 events in risk period; 15.1 events in control period 2007–2008: 23 events in risk period; 16.7 events in control period	RR of GBS onset (all ages) 1–42 days after influenza vaccination during the 2005-2006 season: 0.83 RR of GBS onset (all ages) 1–42 days after influenza vaccination during the 2006–2007 season: 1.13 RR of GBS onset (all ages) 1–42 days after influenza vaccination during the 2007–2008 season: 1.37	[68]