Shingles Vaccination May Reduce Dementia Risk

It’s common for medical treatments to cause side effects like headache or upset stomach. Far more rarely, a side effect brings an unexpected benefit. Recent evidence suggests that the shingles vaccine—recommended for adults 50 and older and immunocompromised individuals 19 and older—might also lower the risk of dementia.

Why This Matters

Dementia affects an estimated nine million people in the U.S., a number expected to double by 2060. Most cases lack highly effective treatments, so a safe, inexpensive preventive measure like the shingles vaccine could have enormous impact.

Link Between Shingles and Dementia

• Some studies report that having shingles increases future dementia risk.
• Researchers hypothesized that preventing shingles through vaccination might in turn reduce dementia risk.

Evidence from a Natural Experiment

A recent study published in Nature took advantage of Wales’s 2013 policy: anyone born after September 2, 1933, was eligible for the shingles vaccine, while those born before were not. By comparing nearly 300,000 people—half just older and half just younger than the cutoff—researchers tracked dementia incidence over seven years.

They found that vaccinated individuals had a markedly lower rate of dementia than those who did not receive the vaccine.

Limitations and Next Steps

• This observational “natural experiment” cannot prove causation, only a strong association.
• Additional research is needed to confirm the benefit, determine which dementia types are most affected, and assess how protection changes over time.
• Understanding biological plausibility—how a herpes zoster vaccine might impact brain health—will help interpret these findings.

Unanswered Questions

• Why did women show more dementia protection than men after vaccination?
• Does the vaccine reduce risk for Alzheimer’s disease specifically or other forms of dementia?
• How durable is the protective effect over many years?

What You Can Do

While healthy behaviors—regular activity and a balanced diet—remain key to lowering dementia risk, growing evidence suggests adding shingles vaccination to preventive strategies. If you’re eligible, get your shingles vaccine: it prevents painful shingles episodes and may help protect your brain.