Herpes Zoster Vaccination Delays Dementia by 20%

A natural experiment on the effect of herpes zoster (shingles) vaccination on dementia offers additional evidence of a dementia-preventing or dementia-delaying effect from zoster vaccination that is less biased than the existing associational evidence.

This new finding is vital as dementia affects more than 55 million people worldwide, with an estimated 10 million new cases every year.

A pivotal study published in the journal Nature on April 2, 2025, reinforces the evidence that standard shingles vaccines may significantly protect older adults against dementia.

Researchers from Stanford Medicine and the Vienna University of Economics and Business analyzed health records of Welsh adults aged 71 to 88.

They found that vaccinated individuals were about 20% less likely to develop dementia over the next seven years compared to those who were not vaccinated.

The authors cautioned that prior studies linking vaccines to improved health outcomes often face scrutiny because vaccinated individuals tend to have healthier behaviors.

In a press release, Dr. Pascal Geldsetzer, the study's senior author, stated, "These associational studies struggle with a fundamental issue: people who get vaccinated generally have different health behaviors than those who don't."

This new finding underscores the need for further research to understand the shingles vaccine's benefits for older adults fully.

According to the U.S. CDC, shingles causes a painful rash. It results from the reactivation of the varicella-zoster virus in adults who typically contracted chickenpox in childhood. The virus stays dormant in the nerve cells for life. In people who are older or have weakened immune systems, the dormant virus can reactivate and cause shingles.

Previously, the journal BMC Public Health published results from a study on October 2, 2023, concluding that both the zoster vaccine for preventing shingles/herpes zoster and the influenza vaccine were associated with a diminished risk of dementia.

This study concluded that the association of herpes-zoster vaccination appeared more pronounced.

And a non-peer-reviewed study published on May 25, 2023, reported that shingles vaccinations were associated with a 19.9% lower risk of dementia.

As of April 2025, various shingles vaccines are offered globally.

Furthermore, the U.S. CDC recommends vaccinations for eligible seniors, which are available at clinics and pharmacies.