Researchers have shown that varicella-zoster virus (VZV), which commonly causes chickenpox and shingles, may activate herpes simplex (HSV), another common virus, to set the early stages of Alzheimer’s disease. Normally HSV-1- one of the main variants of the herpes simplex virus lies dormant within the neurons of the brain. However, when it is activated it leads to the phosphorylation of tau protein, accumulation of amyloid beta proteins, and loss of neuronal function which leads to Alzheimer’s disease. Studies suggest that the pathway to Alzheimer’s disease caused by a VZV infection creates inflammatory triggers that awaken HSV in the brain. This suggests that HSV-1 could play a crucial role in the pathogenesis of Alzheimer’s disease.
