With an estimated 10 million new cases of dementia each year worldwide, the scientific community is intensifying its search for effective ways to prevent or slow its development. In addition to well-known lifestyle factors, new scientific data has highlighted an unexpected protective weapon: the shingles vaccine.
Vaccine that could protect the brain
An analysis by researchers at Stanford School of Medicine found that older adults vaccinated against shingles were 20 percent less likely to develop dementia within seven years, compared with unvaccinated people. The study, published recently in Nature, supports the hypothesis that viruses that affect the nervous system may increase the risk of dementia.
Further, another study published in Cell found that the same vaccine could slow the progression of dementia even in those already diagnosed.
Shingles, caused by the varicella-zoster virus, is a painful infection that recurs years after the initial chickenpox infection. Meanwhile, dementia affects over 55 million people globally, making research into the factors that influence its development an international priority.
Previous studies have suggested a link between the vaccine and a reduced risk of dementia, but could not rule out the influence of the lifestyle of vaccinated people.
A major research priority came from the vaccination program in Wales, which on September 1, 2013, decided to vaccinate only people who were exactly 79 years old. Those who were 78 or 80 were not immediately included.
This created a rare opportunity: comparing two nearly identical groups, as if they were part of a clinical trial.
The analysis included data from more than 280,000 seniors and yielded clear results.
What did the researchers discover after 7 years?
A 37% decrease in cases of herpes zoster among those vaccinated.
20% reduction in the risk of dementia compared to the unvaccinated.
Fewer cases of mild cognitive impairment within 9 years.
In people already diagnosed with dementia, the vaccine was associated with higher survival and slower progression of the disease.
