The present invention relates to a composition comprising at least one mimotope of an epitope of alpha-synuclein for use in a method for preventing and/or treating ß-amyloidoses including Alzheimer's disease, wherein said at least one mimotope is coupled or fused to a pharmaceutically acceptable carrier protein selected from the group consisting of a non-toxic diphtheria toxin mutant, keyhole limpet hemocyanin (KLH), diphtheria toxin (DT), tetanus toxid (TT) and Haemophilus influenzae protein D (protein D).