A safe and effective vaccine to prevent, slow, halt or reverse progression of Alzheimer's disease in human patients is disclosed. The vaccine includes Aβ1-42 or an beta amyloid self epitope (e.g. Aβ1-15, or other 7-mer or 15-mer peptide epitopes derived from Aβ1-42) conjugated to an immunogenic carrier (e.g. DT) formulated in a water-in-oil Th2-biased adjuvant/delivery system.