Regular vaccinations may reduce the risk of dementia—experts have some surprising ideas about how to do it

The shingles vaccine shot prevents relapse, which can prevent the virus from causing inflammation in the brain that can lead to dementia. In fact, there is some evidence that they have shingles may increase the risk of dementia.

A possible way

But not every vaccine linked to a reduced risk of dementia comes with this explanation of how it might protect the brain. For example, the seasonal flu vaccine seems to reduce depression, but it’s not clear how it might work. However, in a large classic study published last monthresearchers have also confirmed the link between the seasonal flu shot and a lower risk of dementia, this time finding that the high-dose long-term shot given to elderly patients is more protective against dementia than the standard dose.

In other words, there appears to be a dose-dependent response—the higher the dose of flu vaccine, the lower the risk of dementia. The authors do not speculate on how climate change can affect cognitive health, but they want to investigate more about possible mechanisms, including adequate protection.

In a March hypothetical article, published in the journal Frontiers in Immunology, Devine and colleagues speculate that trained immunity to vaccines may indeed be responsible.

“The central point of this immunological model is that uncontrolled or excessive neuro-inflammation, which is associated with a high risk of dementia, can counteract the epigenetic reprogramming of the inherited cells,” they write.

For example, it could be that transient changes in the innate immune response from vaccines can block both target and non-target pathogens, preventing brain inflammation from developing, he says.

At the moment, this idea is just an idea, and there is a lot of work needed to prove it. But there are many difficulties in tracking this, the researchers argue. “Elucidation of these current and prospective mechanisms may open new avenues to promote healthy aging through vaccines and may be critical to reducing the global burden of dementia,” they write.