Current Concepts and Future Prospects for Alzheimer Disease Vaccines

Alzheimer disease (AD) is the most prevalent form of dementia worldwide and is characterized by the progressive accumulation of the 42-residue amyloid β protein (Aβ) in brain regions serving memory and cognition. Only a few years ago, the proposition that AD may be amenable to any kind of therapy would have met with considerable skepticism. Yet, recent, exciting developments appear to suggest that immunizing against Aβ may bear some potential for arresting or even curing AD. However, a clinical trial of vaccination with synthetic human Aβ in AD patients was halted because of the development of meningoencephalitis in some patients. Further studies aimed at elucidating the mechanism of Aβ clearance upon Aβ immunization are needed. Such knowledge might facilitate the design of specific vaccination regimens, allowing exclusive targeting of Aβ plaques without inducing detrimental side effects.