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.
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.