Immunization with two experimental vaccines targeting the toxic forms of amyloid-beta and tau protein — two hallmarks of Alzheimer’s disease — triggered an immune response that reduced the levels of both proteins in the brain of a mouse model of the disease. The new combination vaccine, which could enter human trials within two years, could become a potential treatment to delay or slow down disease progression. The findings were published in an article, “Testing a MultiTEP-based combination vaccine to reduce Aβ and tau pathology in Tau22/5xFAD bigenic mice,” in the journal Alzheimer’s Research & Therapy. Current clinical trials have primarily tested therapies that target either amyloid-beta plaques or tau tangles, yet this approach has failed to delay disease progression. Neuroimaging studies support that the interaction between amyloid-beta and tau promote the neurodegeneration and cognitive decline that characterize Alzheimer’s. "Therefore, combinatorial therapies that concurrently target both [amyloid-beta] and tau might be needed for effective disease modification," the researchers wrote. In line with this hypothesis, scientists at the Institute for Molecular Medicine, University of California, Irvine, and Flinders University, in South Australia, targeted both amyloid-beta and tau aggregates in the hopes of providing a more powerful therapeutic strategy to delay Alzheimer's. In a previous study, the team had developed both an amyloid-beta and tau-targeting vaccine, called AV-1959R and AV-1980R. When given to healthy mice, these vaccines induced a powerful antibody response against these proteins. The vaccines were generated using a specific type of technology, called MultiTEP, which generates very high levels of antibodies.