Sage Advice^®

When we think about vaccines, our minds often go to protection against the flu, pneumonia, or shingles—illnesses that can be especially concerning for older adults. But a growing body of research suggests vaccines may do more than shield us from infections. They might also play an unexpected role in lowering the risk of dementia. While this is not yet definitive, the evidence is intriguing—and worth sharing.

The Science Emerging
In recent years, several studies have found a potential link between common vaccines and a reduced risk of cognitive decline. For example, older adults who received flu, pneumonia, or shingles vaccines were found to have a lower incidence of Alzheimer’s disease compared to those who did not. Scientists believe that vaccines may stimulate the immune system in a way that helps clear harmful proteins in the brain, or reduce harmful inflammation—both of which are associated with dementia.

While the exact mechanisms are still being studied, the evidence is promising: these everyday preventive measures may also provide long-term protection for the brain.

Why This Matters
Dementia, including Alzheimer’s disease, affects millions of people worldwide and has profound impacts on families and communities. At Sage Collective®, we emphasize the importance of vibrant living—taking proactive steps to nurture not just our bodies, but our minds and spirits. If something as simple as a routine vaccine can contribute to brain health, it underscores the power of prevention and the interconnectedness of our health choices.

A Broader View of Wellness
Vaccination is just one piece of a larger wellness puzzle. At Sage Collective®, we encourage a holistic approach to healthy aging: nourishing meals, regular physical activity, meaningful social connection, spiritual enrichment, and ongoing learning. Adding vaccine awareness into this mix expands our toolkit for living with vitality and resilience.

Possible Mechanisms
Researchers are still piecing together why vaccines might have this effect. Some leading theories include:

1. Reduced systemic and neuroinflammation – Fewer infections means fewer inflammatory cascades that can damage neurons.
2. Immune system “training” – Vaccines may recalibrate the immune system to respond better to harmful proteins in the brain.
3. Prevention of viral reactivation – Shingles vaccines prevent reactivation of varicella-zoster virus, which may reduce neural damage.
4. Adjuvant effects – Some vaccines, especially newer ones like Shingrix and RSV, include immune-boosting adjuvants that may have additional protective benefits.

Looking Ahead
It’s important to note that research is ongoing, and vaccines are not a guarantee against dementia. But the possibility that they may reduce risk offers hope and reinforces the value of staying up to date with recommended immunizations.

As scientists continue to explore this exciting connection, we can continue doing what we know supports longevity and joy: making intentional choices that keep us strong, engaged, and connected.

Key Studies & Findings
Here are several notable research efforts that have investigated associations between vaccination and reduced dementia or Alzheimer’s disease (AD) risk:

Influenza (Flu) Vaccination

• Bukhbinder et al., 2022: A nationwide U.S. study found that flu vaccination was linked to a lower risk of Alzheimer’s disease in adults aged 65+.
• Zhao et al., 2024 (UK Biobank): Repeated flu vaccinations correlated with progressively lower dementia risk, showing a clear dose–response relationship.
• Yang et al., 2025 Meta-analysis: Involving nearly 10 million participants, this study found the strongest protective effect in high-risk populations (e.g. vascular disease, COPD).

Pneumococcal Vaccination

• Huo et al., 2024: Using the IBM MarketScan database, researchers found pneumococcal vaccination was linked to a 63% lower odds of Alzheimer’s disease.
• Duke University Cardiovascular Health Study: Vaccination between ages 65–75 was associated with a 25–30% reduction in Alzheimer’s risk.

Shingles (Herpes Zoster) Vaccination

• Harris et al., 2023: Shingles vaccination was associated with about a 25% lower Alzheimer’s risk in adults 65+.
• Taquet et al., 2024 (Nature Medicine): The Shingrix vaccine was linked to a delay in dementia onset—about 164 additional dementia-free days.
• Welsh Natural Experiment, 2025: Those eligible for shingles vaccination (based on birthdate rules) had a 20% lower incidence of dementia over seven years.

Tdap / Td (Tetanus, Diphtheria, Pertussis) Vaccination

• Harris et al., 2023: The same large cohort study found that Tdap/Td vaccination was associated with a ~30% lower risk of Alzheimer’s disease.
• Taquet et al., 2024 (Nature Medicine): Found a smaller but measurable protective effect of Tdap, with vaccinated individuals experiencing modest delays in dementia onset.

RSV (Respiratory Syncytial Virus) Vaccination

• Oxford University, 2024: Recipients of the new Arexvy RSV vaccine showed a 29% reduction in dementia diagnoses over an 18-month period.

Caveats & Open Questions
It’s important to note:

• Most findings are observational, not proof of causation.
• Healthier adults may be more likely to get vaccinated, creating “healthy-user bias.”
• Dementia is often underdiagnosed or misclassified, which may affect results.
• Effect sizes vary: shingles and pneumococcal vaccines seem to show stronger associations than flu or Tdap, but evidence is still emerging.

What We Can Do Today
While the science is evolving, the message is clear:

• Stay up to date with recommended vaccinations (flu, pneumococcal, shingles, Tdap boosters, RSV if eligible).
• Consider that these vaccines may offer double protection—against infections and potentially against cognitive decline.
• Continue investing in a holistic approach to brain health: regular exercise, nutritious food, social engagement, spiritual well-being, and lifelong learning.

As we embrace choices that nurture body, mind, and spirit, vaccines may now be one more tool in the toolkit for a longer, healthier, and more joyful life.