A new study found that Varicella and Herpes viruses might interact to cause Alzheimer’s disease.
The study, conducted by the Tufts University found that common viruses might cause inflammation and accumulation of Alzheimer’s associated proteins in the brain.
Researchers also discovered that vaccines for one of the viruses appear to reduce the chances of developing Alzheimer’s.
The virus responsible for chickenpox and shingles may activate a dormant herpes virus strongly associated in its active state with Alzheimer’s disease.
“We have been working off a lot of established evidence that herpes viruses have been linked to increased risk of Alzheimer’s disease in patients,” said Dr David Kaplan, professor at Tuft’s School of Engineering. “We know there is a correlation between herpes viruses and Alzheimer’s disease, and some suggested involvement of Varicella, but what we didn’t know is the sequence of events that the viruses create to set the disease in motion. We think we now have evidence of those events”.
According to the World Health Organisation, an estimated 3.7 billion people under the age of 50 have been infected with HSV-1 which is the virus that causes oral herpes. In most cases it is asymptomatic, lying dormant within nerve cells.
When activated, it can cause inflammation in nerves and skin, causing painful open sores and blisters. Most carriers – and that’s one in two Americans – will have between very mild to no symptoms before the virus becomes dormant.
Varicella virus is also extremely common, with about 95 per cent of people having been infected before the age of 20. Many of those cases are expressed as chickenpox.
VZV, which is a form of Herpes virus, can also remain in the body, finding its way to nerve cells before they becoming dormant.
Dr. Heather M. Snyder, Alzheimer’s Association vice president, said: “Any potential therapy needs to be evaluated in multiple, rigorous human studies. There are several ongoing studies using antivirals at the moment.”
