immune responses after a booster immunisation with ixiaro® in elderly compared to young individuals.

Conditions: Japanese Encephalitis Vaccine

Summary: the aim of this study is to investigate the immune responses following a booster immunisation with the japanese encephalitis vaccine in elderly subjects (above 60 years of age) in comparison to a young study group.

the condition under investigation is the naturally aging immune system. the aim of this study is to investigate the immune responses following a booster immunisation with the japanese encephalitis vaccine in elderly subjects (above 60 years of age) in comparison to a young study group.testing the difference of the jev-antibody titre increase between young and elderly adults between visit 1 (before booster vaccination) and up to visit 4 (6 months after booster vaccination). testing cellular immunity (cytokine production after jev as well as tbe stimulation) on visit 1, 2 (one week after booster immunisation) and 3 between both age groups. testing of surface markers of different t and b cell subsets before and after je-booster vaccination (on visit 1-3) in comparison between both age groups. testing tbe-antibody titres before and after je-booster vaccination (on visit 1-4) in both age groups. testing cmv serology at visit 1 in both age groups.

Eligibility criteria:
inclusion criteria: * participation in the preceeding study "ixiaro®-senescence" (eudractno: 2010-018630-52) without protocoll violation or 2 documented ixiaro® vaccinations 28 days (-8/+ 30 days) apart between january 2010 and april 2014 at the age of 18 to 40 years or above the age of 60. * good state of health including individuals with medically controlled minor underlying disease (such as hypertension, hypercholesterinemia, niddm) * willingness to sign written informed consent major exclusion criteria: * already received an booster (3rd dose) of ixiaro ® * vaccination with other je vaccine (e.g. je-vax) * clinically manifest infection with another flavivirus within 1 year prior study inclusion (yellow fever, dengue fever, west nile, tbe) * past infection with the jev * vaccination against yellow fever, dengue, west nile within 6 months prior to study inclusion * tbe vaccination within the last 30 days prior to study inclusion * immunosuppressive therapy (intake\>14d) within 30 days before ixiaro booster till v3 (day 42+/-4), corticosteroids like prednisolon \> and = 20mg/day; allowed: topic or inhalative application * immunodeficiency or st. p. organ transplantation * autoimmune disease except vitiligo or diseases of the thyroid gland with thyroid hormon substitution therapy * immuntherapy within 2 weeks before or after ixiaro booster * current acute infection or exacerbation of a chronic illness * cancer within the last 5 years * clinically significant haematological, renal, pulmonary, hepatic, neurological, cardiovascular disease which is not treated adequately within 12 weeks before ixiaro booster * known infection with hiv, hep b and hep c * guillain - barré- syndrome (gbs) - anamnestic * anamnestic anaphylaxie, atopy oder severe hypersensivity against ingredients of ixiaro * drug abuse/alcohol abuse * pregnancy and breastfeeding * plasma donation within the last 4 months * receiving blood or immunglobulins within 3 months before v1 * significant mental disorder

Keywords: japanese encephalitis vaccine immune responses