Disclosed herein are DNA-based vaccines against amyloid β peptide for use in treating and alleviating Alzheimer's Disease and related conditions. A DNA construct comprising DNA encoding one or more amyloid β peptides, such as amino acids 1-11 of Aβ, and DNA encoding a hepatitis B antigens, is administered with an adjuvant or by electroporation. The vaccine can also be formulated using a fusion protein expressed by the disclosed DNA, in combination with an adjuvant.