In the last decade, scientists have improved our understanding of the immune system — leading to the development of immunotherapies for different diseases including Alzheimer’s. Aduhelm and other monoclonal antibodies bind to plaques, flagging them for clearance by the brain’s immune cells.
But what if the immune system was trained to recognize and clear disease-associated plaques on its own?
Many vaccines against infectious diseases have been developed, and scientists have found these same principles can be used to fight Alzheimer’s.
Currently, at least nine vaccines are being tested in clinical trials. All vaccines are close, a few years, at least, to the finish line; the most advanced candidate will soon move forward into Phase 3 trials, the final stage before applying for approval from the Food and Drug Administration.
Targeting Amyloid and Tau
Toxic beta-amyloid protein plaques and tau tangles build up in the brains of those with Alzheimer’s disease. Some vaccines focus on introducing amyloid and tau proteins to the body’s immune system, training the body to identify these pathological proteins and destroy them.
Vaxxinity’s UB-311 vaccine has shown promise in Phase 2a trials and is working on plans for a 2022 Phase 2b trial. This vaccine consists of a protein that mimics a part of the beta-amyloid plaque. It trains immune cells to later recognize, bind and clear the plaque. The vaccine is delivered in three doses, with regular boosters. The clinical trials underway will ultimately determine whether UB-311 is capable of reducing the severity — or even preventing the development — of Alzheimer’s.
Priming the Immune System
Other approaches for Alzheimer’s vaccines are focused on stimulating the immune system, so that it is more likely to mount a response to amyloid plaques and tau tangles on its own.
Researchers at the Brigham and Women’s Hospital recently tested the potential of a vaccine using this strategy. Protollin is an intranasal vaccine that stimulates the cells of the immune system. It is an adjuvant, meaning it enhances the immune response and is a common component of many other standard vaccines. After promising results in a mouse model of Alzheimer’s, the vaccine is moving forward to Phase 1 clinical trials, where researchers will assess its safety in humans.
Despite these many advances, it may still be five to ten years until a vaccine candidate completes clinical trials. These clinical trials — and the participants who volunteer to make them possible — may lead to the development of a new class of Alzheimer’s therapeutics.
To learn about clinical trials of new medications that aim to modify the pathology of Alzheimer's disease, call Charter Research at 407-337-1000 (Orlando) or 352-775-1000 (The Villages).