The number of Americans developing dementia is expected to increase from 514,000 in 2020 to about 1 million by 2060, recent research estimates. While there are few effective treatments for dementia and no preventive measures outside of lifestyle changes, the shingles vaccine may hold promise.
A new study suggests that the shingles vaccine reduces the risk of developing dementia by 20 percent, equivalent to a 3.5 percent reduced probability of being diagnosed with dementia over a seven-year follow-up period. This effect was observed even after accounting for possible confounding variables.
Researchers conducted a natural experiment using Wales’ shingles vaccination program in 2013, which created a unique comparison group. Only Welsh adults born on or after September 2, 1933, were eligible for the vaccine, while those born before that date were ineligible. This setup allowed researchers to compare two groups of people with nearly identical backgrounds and ages who either received or missed the vaccine.
The study’s findings align with previous research, which has suggested that shingles vaccines may reduce dementia risk due to their effect on reducing varicella-zoster virus reactivations. Reactivations of this virus have been linked to increased dementia risk, potentially due to inflammation caused by the reactivation.
Another possible mechanism is the vaccine’s broader effect on activating the immune system, which may be beneficial in delaying or preventing dementia. However, more research is needed to confirm these findings and determine the specific mechanisms at play.
The Centers for Disease Control and Prevention recommends two doses of a shingles vaccine for adults 50 and older. While the vaccine has not been shown to prevent dementia outright, it may have a larger effect than current dementia therapeutics when considered as a one-off intervention that is inexpensive and readily available.
Source: https://www.washingtonpost.com/wellness/2025/04/08/shingles-vaccine-dementia-risk-reduce