The recombinant shingles vaccine is associated with lower risk of dementia, 2024, Dercon et al

The recombinant shingles vaccine is associated with lower risk of dementia

Quentin Dercon, John A. Todd, John A. Todd, Paul J. Harrison

Published: 25 July 2024

Abstract
There is emerging evidence that the live herpes zoster (shingles) vaccine might protect against dementia. However, the existing data are limited, and only refer to the live vaccine now discontinued in the USA and many other countries in favour of a recombinant vaccine. Whether the recombinant shingles vaccine protects against dementia remains unknown.

Here we used a natural experiment opportunity created by the rapid transition from the use of live to the use of recombinant vaccines to compare the risk of dementia between vaccines. We show that the recombinant vaccine is associated with a significantly lower risk of dementia in the 6 years post-vaccination. Specifically, receiving the recombinant vaccine is associated with a 17% increase in diagnosis-free time, translating into 164 additional days lived without a diagnosis of dementia in those subsequently affected. The recombinant shingles vaccine was also associated with lower risks of dementia compared to two other vaccines commonly used in older people: influenza and tetanus/diphtheria/pertussis vaccines. The effect was robust across multiple secondary analyses, and present in both men and women but greater in women.

These findings should stimulate studies investigating the mechanisms underpinning the protection and could facilitate the design of a large-scale randomised control trial to confirm the possible additional benefit of the recombinant shingles vaccine.

Link (Nature Medicine) [Paywall]

 

We've got a study and thread here

 

Researchers Are Exploring the Role of Shingles-and a Protective Role of Shingles Vaccine- in Dementia

As Geldsetzer and Warren-Gash pointed out, why vaccines may promote brain health isn’t clear. Do they reduce dementia risk by preventing infections? Or is there something else about adult vaccines—some effect unrelated to their target infections—that ends up protecting the brain?

The University of Michigan Health and Retirement Study, a longitudinal study that surveys a representative sample of 20 000 people aged 50 years or older in the US.

Ukraintseva and her coauthors found that shingles, pneumonia, and fungal infections diagnosed from ages 65 to 75 years were all associated with a significantly increased risk of Alzheimer disease later in life, by 16% to 42%, while the live-attenuated shingles vaccine and the pneumococcal vaccine (PPSV23) administered at those same ages were associated with a significantly lower risk of Alzheimer disease, by 15% to 21%.

Vaccines can slightly rejuvenate the aging immune system, although live and nonlive vaccines could have different effects, Ukraintseva explained. “We must also see how these vaccines affect other causes of death,” she added.
LINK

 

Brain disorders such as dementia are linked to viral infections. Scientists are finding out why

For Dr Nazareth, noses are a particularly important point of brain entry for viruses, as it can allow them to bypass the blood-brain barrier.

"The nose is the shortest distance from the outside world to your brain.

"It doesn't happen that often … but it's one of the bypasses that a pathogen could use to get into the brain without the barrier."

But viruses might not even need to enter the brain to cause damage. Even just being near it might be enough.

Seasonal influenza is a good example of this, according to Dr Nazareth.

Only in extremely rare cases has it been seen to infect the brain, but despite this, it can still cause brain inflammation.

"Even if the virus stays within your nose, there's inflammation there," she said.

The inflammation can causes immune signals to be released, which can cross into the brain and increase inflammation in the brain itself.

"The virus doesn't need to get in to cause disease," Dr Nazareth said.

 

I've also read accounts of doctors advising patients to stop picking their nose.