MAPT and Alzheimer disease: We show for the first time a different mechanism in which active DNA Aβ42 trimer immunization in the 3xTg-AD mouse model results in reduction of both pathologies with one vaccine: Aβ reduction due to antibodies generated against Aβ and tau reduction due to an indirect mechanism in which less Aβ led to less tau kinase activation and therefore to less tau phosphorylation.