A new study suggests that the shingles vaccine may reduce the chance of developing dementia and slow the progression of the disease in people who have already been diagnosed with the disease.
Researchers are finding further evidence that certain herpesviruses, such as shingles, which can infect the nervous system, may be responsible for dementia.
The initial study, published in the journal Nature, and a follow-up study conducted by Stanford Medicine, published Dec. 2 in the journal Cell, show that vaccination against shingles may have a therapeutic effect on dementia by slowing the progression of the disease and reducing the likelihood of death.
These findings are promising for people battling dementia. Dementia cases are expected to rise in the coming years, with the lifetime risk of dementia after age 55 potentially rising to 42%, a much faster pace than expected, according to a study published in 2024.
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“We know that it has an effect on the probability of dying from dementia in people who already have dementia,” Dr. Pascal Geldsetzer, assistant professor of medicine at Stanford University and senior author of the new study, said of the potential effectiveness of the shingles vaccine in a recent interview with CNN.
“This means that the vaccine not only has preventive potential, but it also has real therapeutic potential, because we’ve already seen some efficacy among people with dementia,” he said. “For me, this was really exciting and unexpected.”
Link: Shingles and dementia
The varicella-zoster virus is a type of herpesvirus that causes both chickenpox and shingles. Even after you have fully recovered from chickenpox, the virus remains latent in your body. According to the Centers for Disease Control and Prevention, the shingles virus often causes no further problems, but it can come back years later and cause shingles, a painful rash.
The CDC estimates that approximately 1 in 3 people in the United States will develop shingles in their lifetime. Shingles can be prevented with a two-dose vaccine, which is approximately 90% effective in preventing shingles in the elderly. The CDC recommends getting the vaccine once you turn 50.
The findings support a growing theory that viruses that affect brain function may increase the risk of dementia. According to Alzheimer’s International, more than 55 million people worldwide suffer from dementia.
Scientists believe that shingles vaccination may help prevent the reactivation of dormant viruses such as varicella zoster and herpes simplex, which are thought to contribute to the buildup of dangerous proteins associated with brain inflammation and dementia. How it works is still unknown.
Another theory, according to Cardiff University in Wales, is that the vaccine could strengthen the immune system more broadly and prevent age-related decline in immunity.
Scientists note that further research is needed to confirm the results and better understand how vaccines affect brain health.
