Breakthroughs in research offer hope not only for successfully treating but also for eliminating Alzheimer’s disease. This was the finding of New Scientist journalist Graham Lawton, who reviewed the history and status of research on dementia and Alzheimer’s disease. In particular, exciting new Alzheimer’s vaccine research holds promise for preventing Alzheimer’s disease.
A monumental health crisis is looming
Alzheimer’s disease accounts for almost 80% of dementia cases. With an aging global population, scientists expect the number of people living with Alzheimer’s to triple by 2050. This disease has devastating effects on individuals, their families, and healthcare systems.
Scientists have been trying to understand and treat Alzheimer’s disease for decades. It’s a neurodegenerative condition that slowly erodes the brain. Researchers have rejected many therapies that seemed promising in the lab because they didn’t prove helpful in human trials or had too many serious side effects. Today, a few approved drugs are on the market that have some success in slowing the progression of the disease, but no cure is available.
Causes of Alzheimer’s Disease
Dr. Alois Alzheimer diagnosed a female patient with a neurodegenerative disease, and after she died in 1906, Dr. Alzheimer discovered significant changes in her brain. These changes included abnormal protein deposits between neurons and tangled proteins within neurons. The deposits were identified in the 1980’s and called beta-amyloid, and the tangles were made up of a protein named tau.
The “amyloid cascade hypothesis” became the prevailing explanation for the development of Alzheimer’s disease. The idea is that the amyloid plaques develop and trigger the tau tangles, leading to dysfunction and brain cell death. Some scientists have posited that bacteria entering the brain causes plaques to develop as an immune overreaction. Others believed that neuroinflammation caused by tau proteins is the root of the problem.
The long pathway to finding treatments for Alzheimer’s
The lack of a clear understanding of how Alzheimer’s develops led to various attempts at treatment. For example, for 20 years scientists targeted the beta-amyloid plaques with various drugs, but none of them worked in humans, and some had serious side effects.
Scientists also sought to use the body’s own immune system to fight Alzheimer’s disease. By using vaccines, they hoped to generate antibodies against beta-amyloid proteins. Early attempts were successful in animal models but not in humans. A newer method uses lab-created monoclonal antibodies to specifically target amyloid. They deliver lots of short-acting antibodies but unlike vaccines, they don’t engage the immune system itself. This method was finally successful in reducing the decline in patients. The FDA has approved three monoclonal drugs (aducanumab, lecanemab, and donanemab) for Alzheimer’s disease.
These new drugs were the first to show that attacking amyloid improved cognition, marking a major step forward in understanding the cause of the disease. However, monoclonal drugs are far from perfect. They require time-consuming infusions, are extremely expensive (over US$25,000 per year), and a proportion of patients experience swelling or bleeding in the brain.
Vaccine options may be successful in eliminating Alzheimer’s disease
Researchers have renewed interest in vaccines to generate antibodies against beta-amyloid. Lawton reported that several pharmaceutical companies are currently working on this approach. Vaxxinity developed a vaccine and tested it in a Phase II clinical trial in Taiwan. The drug was safe, created a strong immune response by making the body produce its own antibodies, and slowed cognitive decline by 50%. This result is twice as effective as a currently approved drug like lecanemab. The vaccine did not cause brain swelling or bleeding, is relatively inexpensive, and is easier to administer. Phase III trials should start soon.
Reducing tau tangles is challenging because they’re usually protected inside cells. However, a new vaccine against tau is currently being evaluated in clinical trials. It causes the body to produce antibodies that attack tau tangles when they’re outside cell walls.
A monoclonal drug named foralumab is being tested to activate T-cells that can reduce inflammation in the brain, which is often a symptom of amyloid plaques and tangles in the brain. The drug can be administered nasally and should go into human trials shortly.
“The outright prevention of Alzheimer’s disease has become a realistic goal,” Dennis Selko, MD, of Harvard Medical School told Lawton.
Finally, a new blood test enables early intervention against Alzheimer’s because it identifies tau tangles long before symptoms of Alzheimer’s appear. The patient could then be vaccinated to keep the disease from advancing. One anti-tau vaccine is using this method to test whether Alzheimer’s could be prevented.
What can be done now to prevent dementia and Alzheimer’s disease
This new vaccine research brings hope for treating, preventing, and eliminating Alzheimer’s disease. In the meantime, several lifestyle changes can make a difference in reducing the risk of dementia. The Parsemus Foundation is also supporting research on the impact of fish oil, testosterone, and lithium on Alzheimer’s disease.
