A team of researchers led by an Indian-American scientist are working on a vaccine they hope could prevent Alzheimer’s disease by targeting a specific protein commonly found in the brains of patients affected by the neurodegenerative disorder. 

Dementia is a syndrome in which there is deterioration in memory, thinking, behaviour and the ability to perform everyday activities. Although dementia mainly affects older people, it is not a normal part of ageing. Worldwide, around 50 million people have dementia, and there are nearly 10 million new cases every year. Alzheimer's disease is the most common form of dementia and may contribute to 60–70% of cases. In India, more than 4 million people have some form of dementia, says a study. 

Researchers at the University of New Mexico (UNM) led by Dr. Kiran Bhaskar, associate professor in the varsity’s Department of Molecular Genetics & Microbiology, have started to test the vaccine on mice. Bhaskar, who published a paper in NPJ Vaccines last week, says the work started with an idea in 2013. “I would say it took about five years or so to get from where the idea generated and get the fully functioning working vaccine,” he said.

“We used a group of mice that have Alzheimer’s disease, and there were a series of injections,” said Nicole Maphis, a PhD student and Bhaskar’s associate. She said the vaccine targets a specific protein known as tau that’s commonly found in the brains of Alzheimer’s patients.

“These antibodies seem to have cleared out pathological tau (pTau). Pathological tau is one of the components of these tangles that we find in the brains of patients with Alzheimer’s disease,” she explained. 

Normally a stabilising structure inside of neurons, Tau is a protein that when it occurs in tangled formations in the brain of Alzheimer’s patient, disrupt the ability of neurons to communicate with one another in the brain.

The mice were then given a series of maze-like tests. The mice that received the vaccine performed a lot better than those that hadn’t. MRI scans also showed that the vaccinated animals had less brain shrinkage, suggesting that the vaccine prevents neurons from dying.

The team also found significantly fewer tangles in both the cortex and the hippocampus — areas in the brain that are important for learning and memory, and which are destroyed in Alzheimer’s.

“We’re excited by these findings, because they seem to suggest that we can use the body’s own immune system to make antibodies against these tangles, and that these antibodies actually bind and clear these tau tangles,” Maphis told the UNM health sciences newsletter. 

However, drugs that seem to work in mice do not always have the same effect in humans. A clinical trial involving people will be required to see if the drug helps in real life, and that’s a difficult and expensive undertaking  with no guarantee of success. “We have to make sure that we have a clinical version of the vaccine so that we can test in people,” Bhaskar said.