A major new study has uncovered compelling evidence that the shingles vaccine may lower the risk of developing dementia. Researchers analyzed the health records of more than 280,000 older adults in Wales and found those who received the Zostavax vaccine were 20% less likely to be diagnosed with dementia over the following seven years.
The findings stem from a natural experiment created by a 2013 Welsh public health policy. Only those born on or after September 2, 1933, were eligible for the vaccine, dividing the older population into two sharply defined groups. This allowed researchers to compare dementia rates in people born just weeks apart but with differing vaccine access.
After adjusting for vaccine uptake, the data revealed a significant reduction in dementia risk, especially among women. The study strengthens growing evidence linking shingles vaccination to cognitive protection, with previous research also pointing to benefits from Shingrix, a newer vaccine.
The exact mechanism remains unclear. Scientists speculate that the vaccine may reduce chronic inflammation in the nervous system by preventing viral reactivation or may trigger broader immune responses that help safeguard the brain. These immune effects could explain the stronger benefit observed in women.
Dementia affects over 55 million people worldwide and remains incurable.
Source: The Guardian, Nature