Use of a compound (I), or its 5-mers, is for preparing a vaccine for Alzheimers disease (AD). Use of a compound (I) or its 5-mers, having a binding capacity to an antibody being specific for the natural N-terminal AB42 sequence Asp-Ala-Glu-Phe-Arg-His, for preparing a vaccine for AD, where (I) comprises the sequence X 1X 2X 3X 4X 5X 6, where X 1 to X 6 is an amino acid, except Cys, and where X 1X 2X 3X 4X 5X 6 is not Asp-Ala-Glu-Phe-Arg-His. Independent claims are also included for: (1) isolating (I) and (2) vaccine against AD comprising antigen which includes at least one peptide, e.g. Glu-Ile-Asp-Gln-Tyr-Arg, Glu-Leu-Tyr-His-Arg, Glu-Val-Asp-Tyr-His-Arg, Asp-Ile-Asp-Tyr-His-Arg, Asp-Leu-Asp-Tyr-His-Arg, Asp-Val-Asp-Tyr-His-Arg, Asp-Ile-Asp-Tyr-Arg-Arg, Asp-Leu-Asp-Tyr-Arg-Arg, Asp-Val-Asp-Tyr-Arg-Arg, Asp-Lys-Glu-Leu-Arg-Ile, Asp-Trp-Glu-Leu-Arg-Ile, Tyr-Arg-Glu-Phe-Arg-Ile, Tyr-Ala-Glu-Phe-Arg-Gly, Glu-Glu-Ala-Glu-Phe-Arg-Gly, Asp-Tyr-Glu-Phe-Arg-Gly, Glu-Leu-Glu-Phe-Arg-Gly, Asp-Arg-Glu-Leu-Arg-Ile, Asp-Lys-Glu-Leu-Lys-Ile, Asp-Arg-Glu-Leu-Lys-Ile, Gly-Arg-Glu-Phe-Arg-Asn, Glu-Tyr-Glu-Phe-Arg-Gly, Asp-Trp-Glu-Phe-Arg-Asp-Ala, Ser-Glu-Phe-Arg-Thr, Asp-Lys-Glu-Lys-Arg, or Ser-Phe-Glu-Phe-Arg-Gly. ACTIVITY : Neuroprotective Nootropic. No biological data given. MECHANISM OF ACTION : Vaccine.
