Two Popular Vaccines Show Surprising Protection Against Dementia

Sometimes, small changes bring unexpected benefits. A person with sore feet might buy orthopedic shoes. Suddenly, their nighttime back pain improves due to better posture. In medicine, small shifts can create similar ripple effects.

A new study shows this may be true for some vaccines. Shingrix and Arexvy protect against shingles and RSV, respectively. But they may also reduce the risk of dementia. The research, published in npj Vaccines, revealed striking results.

Both vaccines contain the immune-boosting adjuvant known as AS01. Shingrix recipients showed an 18% lower risk of dementia. Those who received Arexvy saw a 29% reduced risk. Together, the vaccines lowered dementia risk by 37%.

The results suggest dementia may not be a standalone disease. Instead, it could reflect an immune disorder within the brain. This shifts how we understand, prevent, and possibly treat dementia.

How Do Vaccines Containing AS01 Reduce Dementia Risk?

The study used data from over 436,000 people in the U.S. Researchers matched groups using electronic health records. None of the tested individuals had received shingles or RSV vaccines. After vaccination, participants were tracked for 18 months.

The protection appeared linked to the AS01 adjuvant in the vaccines. The flu vaccine, which lacks AS01, did not reduce dementia risk. Shingrix and Arexvy both contain AS01 and showed strong protection. This suggests AS01, not virus prevention alone, plays a central role.

In mice, AS01 improved Alzheimer’s disease outcomes. This may explain the quick protection seen after human vaccination. AS01 includes two immune stimulators: MPL and QS-21. These activate immune cells and trigger interferon gamma (IFN-γ) production.

IFN-γ may reduce plaque buildup tied to Alzheimer’s disease. It is also linked to better thinking and memory in aging adults. One vaccine likely activates this immune protection to its full extent. That’s why getting both vaccines showed no added benefit.

Shingrix is given in two doses, while Arexvy uses just one. But both offered similar levels of dementia risk reduction. This means the shared adjuvant may be doing the heavy lifting. One vaccine appears enough to trigger this brain-boosting pathway.

Limitations and Future Research Opportunities

The study’s design came with a few key limitations. Being diagnosis-free does not mean entirely disease-free. Dementia can take time to detect and diagnose properly. This may affect how results are interpreted over time.

Some participants may have received a different RSV vaccine. Not all RSV vaccines in the data contained the AS01 adjuvant. If so, the benefit of Arexvy may be underestimated. Better tracking of vaccine brand names would improve future studies.

The study also used electronic health records, not clinical assessments. This limits how precisely researchers can confirm dementia diagnoses. Continued research using clinical validation is needed for stronger conclusions. Still, the data showed consistent and meaningful protection patterns.

Future studies should test how long this protection might last. Researchers also want to know how AS01 works in the brain. Its immune-triggering effects may unlock new treatment possibilities. Understanding these pathways could improve dementia prevention strategies.

Conclusion

AS01-adjuvanted vaccines may offer unexpected protection against dementia. Their immune-boosting ingredients appear to activate brain-protective pathways. These findings could help shape future strategies for dementia prevention.

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Logan Hamilton is a health and wellness freelance writer for hire. He’s passionate about crafting crystal-clear, captivating, and credible content that elevates brands and establishes trust. When not writing, Logan can be found hiking, sticking his nose in bizarre books, or playing drums in a local rock band. Find him at loganjameshamilton.com.