The present invention relates to methods and compositions for treating, preventing, and diagnosing Alzheimers Disease or other tauopathies in a subject by administering an immunogenic tau peptide or an antibody recognizing the immunogenic tau epitope under conditions effective to treat, prevent, or diagnose Alzheimers Disease or other tauopathies. Also disclosed are methods of promoting clearance of aggregates from the brain of the subject and of slowing progression of tau-pathology related behavioral phenotype in a subject.