Daijiworld Media Network- London

London, Apr 3: A groundbreaking study published in Nature has revealed that receiving the shingles vaccine could lower the risk of developing dementia by 20%, with women potentially benefiting more than men. This discovery offers the strongest evidence so far that vaccination against shingles could play a role in reducing cognitive decline.

The research, led by Pascal Geldsetzer of Stanford University, examined health records of over 280,000 older adults. Those who received a now largely discontinued shingles vaccine called Zostavax were found to be 20% less likely to be diagnosed with dementia over the subsequent seven years compared to those who did not receive the vaccine.

“For the first time, we are able to say much more confidently that the shingles vaccine causes a reduction in dementia risk. If this truly is a causal effect, we have a finding that’s of tremendous importance,” Geldsetzer stated.

Link between shingles and dementia

Shingles is triggered by the reactivation of the varicella-zoster virus, which causes childhood chickenpox. The virus can remain dormant in nerve cells for decades and reactivate later in life, particularly among older adults with weakened immune systems. Symptoms include painful blisters, burning sensations, numbness, and chronic nerve pain that can be debilitating.

In the United States, about one in three individuals is expected to develop shingles during their lifetime, with approximately a third of eligible adults opting for vaccination, according to the CDC.

A unique study approach

The researchers utilized vaccination data from a rollout in Wales that began on September 1, 2013. Public health policy at the time made individuals born on or after September 2, 1933, eligible for the Zostavax vaccine, while those born earlier were excluded.

This eligibility cutoff allowed researchers to compare dementia rates among people born just weeks apart, with one group having access to the vaccine and the other not. After adjusting for various factors, the study concluded that vaccinated individuals had a 20% lower risk of dementia, with the most significant reduction observed among women.
Potential mechanisms behind the protection

Although the exact reason for the reduction in dementia risk remains unclear, researchers have proposed several theories. One possibility is that the shingles vaccine reduces inflammation in the nervous system by preventing the virus from reactivating. Another theory suggests that the vaccine may induce broader immune system changes that offer protective benefits.

“It’s important to note that this study looked at the Zostavax vaccine rather than Shingrix, which is now more commonly used,” remarked Julia Dudley, head of research at Alzheimer’s Research UK. “Understanding this link better, including the reason for any differences between men and women, could open new avenues for dementia prevention and treatment.”

The findings highlight the need for further research into the relationship between shingles vaccination and dementia, particularly focusing on how different vaccines might influence the risk and whether similar benefits can be achieved with more commonly used vaccines like Shingrix.