Evidence continues to mount showing that the shingles vaccine may offer benefits beyond preventing a painful rash. A growing body of research suggests it could lower the risk of dementia — including Alzheimer’s disease — and may even slow biological aging.

Accumulating research shows that in addition to protecting against shingles, the vaccine appears to stimulate the immune system in ways that may reduce the risk of age-related cognitive decline, according to Ars Technica.

Early findings emerged from studies of Zostavax, the first shingles vaccine, introduced in 2013. A 2025 study published in Nature found that people who became eligible for Zostavax had a 20% lower rate of dementia compared to slightly older peers who were not eligible. An Australian study similarly reported that age-eligible individuals had 1.8% fewer dementia diagnoses.

More recent research has focused on Shingrix, the newer shingles vaccine approved in 2017. Studies suggest Shingrix may offer comparable — or possibly greater — protection against dementia due to its stronger immune response.

In 2024, a study involving more than 200,000 Americans found that people who received Shingrix experienced a 17% increase in dementia-free time. Another study published in Nature Communications reported that those vaccinated with Shingrix had a 51% lower dementia risk compared to unvaccinated individuals.

What Is Shingles?

Shingles, or herpes zoster, occurs when the varicella-zoster virus — the same virus that causes chickenpox — reactivates later in life. It typically causes a painful rash on one side of the body or face and may be accompanied by burning, itching, or nerve pain.

Anyone who has had chickenpox can develop shingles, but the risk increases with age and weakened immunity.

The Centers for Disease Control and Prevention (CDC) recommends the two-dose Shingrix vaccine for adults age 50 and older, as well as adults 19 and older with weakened immune systems. The vaccine is recommended even for people who have already had shingles. In 2018, the CDC shifted its recommendation from Zostavax to Shingrix.

Why the Dementia Link?

Researchers are still working to understand why the shingles vaccine may reduce dementia risk. Some experts note that women are more likely than men to develop both shingles and dementia, suggesting a possible gender-related factor.

In a recent study examining shingles vaccination and biological aging, researchers found that vaccinated individuals showed lower markers of inflammation and molecular aging, along with improved overall aging scores.

Lead researcher Jung Ki Jim noted that chronic, low-grade inflammation plays a role in many age-related conditions, including heart disease and dementia.

“By helping to reduce this background inflammation — possibly by preventing reactivation of the virus that causes shingles, the vaccine may play a role in supporting healthier aging,” she suggested.

While more research is needed to confirm cause and effect, scientists say the findings add to the growing list of potential benefits associated with shingles vaccination.