Table 1. Study subject characteristics.

	healthy controls	MS IFNβ
	baseline characteristics
N	33	26
median age (years) [range]	38 [19–46]	40 [29–49]
female/male	20/13	22/5
median disease duration (years) [range]	N.A.	3.9 [0.5–12.8]
median EDSS [range]	N.A.	2.5 [1.0–4.0]
median therapy duration (months) [range]	N.A.	44.1 [6–144]
	response to IFNβ-therapy
annualized relapse rate before IFNβ-therapy	N.A.	1.28
annualized relapse rate under to IFNβ-therapy	N.A.	0.59
reduction of annualized relapse rate under IFNβ-therapy	N.A.	0.69 (p = 0.002)
new T2-lesions/year before IFNβ-therapy	N.A.	2.9
new T2-lesions/year under IFNβ-therapy	N.A.	0.8
reduction of new T2-lesions/year under IFNβ-therapy	N.A.	2.1 (p = 0.032)
flu-like symptoms after initiation of IFNβ-therapy	N.A.	69%
flu-like symptoms under established of IFNβ-therapy	N.A.	33%
IFNβ-preparation	N.A.	IFNβ-1a im OW: 9
		IFNβ-1a sc THW: 6
		IFNβ-1b sc EOD: 11
	tolerability of vaccine / incidence of influenza-like illness
injection-site reactions day 0–3 post vaccination	21/33 (64%)	20/26 (77%)
general symptoms day 0–3 post vaccination	6/33 (18%)*	14/26 (54%)*
MS relapses	N.A.	3/26 (12%)
Incidence of influenza-like illness	4/33 (12%)	3/26 (12%)

Characteristics of the study population (upper part), clinical and subclinical response of patients with MS to IFNβ-therpay (middle part) and tolerability of influenza vaccination and incidence of influenza-like illnesses (lower part). Abbreviations: interferon-beta (IFNβ), IFNβv-treated patients with multiple sclerosis (MS IFNβ), not applicable (N.A.), Expanded Disability Status Scale (EDSS), intramuscular (im), subcutaneous (sc), once weekly (OW), three times per week (THW), every other day (EOD).

^*indicates p<0.05.