Scientists in Japan may be at the beginning of a truly monumental achievement: a vaccine that can slow or delay the progression of Alzheimer’s disease. In preliminary research released this week, the vaccine appeared to reduce inflammation and other key biomarkers in the brains of mice with Alzheimer’s-like disease while improving their consciousness. More research will be needed before this vaccine can however, tested on humans.
The experimental vaccine is primarily being developed by researchers from Juntendo University in Japan.
It is intended to work by training the immune system to go after certain ones senescent cells, aging cells that no longer divide to make more of themselves, but instead get stuck in the body. These cells are not necessarily harmful, and some play a vital role in healing and other life functions. But they have also been linked to a number of age-related diseases, including Alzheimer’s. The vaccine specifically targets senescent cells that produce high levels of something called senescence-associated glycoprotein, or SAGP. Other research has suggested that people with Alzheimer’s tend to have brains filled with these cells in particular.
The team tested their vaccine on mice bred to have brains that develop the same kind of gradual destruction seen in people with Alzheimer’s. This damage is thought to be driven by the accumulation of a misfolded form of amyloid-beta, a protein. The mice were divided into two groups, with only one group receiving the actual vaccine.
In the brains of the vaccinated mice, the team found evidence of reduced inflammation and fewer amyloid deposits, along with lower levels of SAGP-expressing cells. These mice also appeared to behave more like typical mice compared to controls. They continued to show anxiety, for example, as they got older—a trait that tends to fade in late-stage people Alzheimer’s. The also showed more awareness of their surroundings during maze tests.
The results were submitted this weekend at the American Heart Association’s Basic Cardiovascular Sciences Scientific Sessions 2023. That means this research hasn’t been formally peer-reviewed yet, so it should be viewed with extra caution. At the same time, the team’s vaccine appears to have met an important criterion that many previous trials have failed to reach.
“Previous studies with various vaccines to treat Alzheimer’s disease in mouse models have been successful in reducing amyloid plaque deposits and inflammatory factors, but what makes our study different is that our SAGP vaccine also changed the behavior of these mice for the better ,” lead author Chieh-Lun Hsiao, a post-doctoral fellow in the Department of Cardiovascular Biology and Medicine at Juntendo University, said in a announcement published by the American Heart Association.
Of course, mouse studies are only the beginning of showing that an experimental drug or vaccine might work as intended. It will take further studies to validate these results and to test the vaccine’s effectiveness safety in humans before large trials even into the picture.
But there have been more recent, if modest, successes in Alzheimer’s treatment as too late, and other trial candidates – including vaccines-is already in clinical trials. With any luck, these newer and upcoming therapies may one day stop Alzheimer’s from being the incurable death sentence it is today.