Scientists at the University of Oxford have found for the first time that infection with the chickenpox virus may increase the risk of developing Alzheimer’s disease.
A combination of the viruses that cause chickenpox and shingles, and the common herpes infection, which is dormant in two-thirds of people under the age of 50, has been found to produce a protein that causes Alzheimer’s disease.
Most people have had shingles or chickenpox at some point in their lives, but it’s possible to get the varicella zoster virus (VZV) several times, especially if you haven’t been vaccinated.
A varicella vaccine, an attenuated version of the live virus, is available in the NHS for health care workers who have never been infected and for those in contact with immunocompromised people.
Most people acquire immunity during childhood through natural infections.
Varicella virus cannot cause dementia by itself
Oxford scientist Professor Ruth Itzaki has been investigating the role of herpes in Alzheimer’s disease for more than 30 years, and found that the common herpes labialis virus damages neurons by creating plaques that cause dementia and Alzheimer’s disease. We have previously proved that it is possible to give
Her latest study, published Tuesday in the Journal of Alzheimer’s Disease, looked at how brain cell herpes (HSV-1) is affected when VZV is present.
The two viruses are closely related and belong to the same family. Experiments have shown that the chickenpox virus does not make the dementia-causing proteins known as beta-amyloid or tau on its own.
However, it not only attempts to destroy pathogens, it also activates the immune system to produce chemicals called cytokines that cause inflammation.
Lab-based research shows that this immune response to the chickenpox virus awakens the herpes virus from its dormant state and begins to make again proteins that destroy the brain.
The researchers say the varicella virus VZV is unlikely to be the direct cause of Alzheimer’s disease, but may have an indirect effect by helping and reviving herpes.
Vaccines could ‘play a bigger role’
Based on early findings, researchers say that repeated, mild VZV infections, if left unnoticed, can lead to flare-ups of brain-damaging herpes, with cumulative effects over time. said.
Professor Itzhaki of the Universities of Oxford and Manchester said, “This surprising result supports that infections like VZV can increase inflammation in the brain and reactivate dormant HSV-1. There seems to be
“Brain damage from repeated infections over a lifetime ultimately leads to the development of Alzheimer’s disease/dementia.
“This means vaccines can play a bigger role than just preventing a single disease, as they can also indirectly prevent Alzheimer’s to some extent by reducing infections.”