Shingles Shot May Protect Against Dementia

Shingles is a viral infection that affects one in three Americans in their lifetime, according to the U.S. Centers for Disease Control and Prevention (CDC). Its symptoms include painful blisters, burning and tingling sensations, and may lead to chronic nerve pain. Shingles, a form of herpes, is caused by the varicella-zoster virus (VZV)—the same virus that causes chickenpox. VZV can remain dormant in nerve cells for decades after having chickenpox. Vaccines for shingles are available, but the CDC reports that only about one-third of Americans over age 50 have been vaccinated. 

It has been hypothesized that shingles contributes to the development of dementia later in life. A study published in the journal Nature sought to investigate that potential causal link by evaluating the affect of the shingles vaccine on dementia diagnoses.

In the study, the researchers leveraged a unique situation in Wales, United Kingdom. The shingles vaccine was offered free of charge to older adults based strictly on their date of birth. Individuals born after September 2, 1933, were eligible for the free vaccine, while those born before that date were not. Nearly half of eligible individuals received the vaccine, while almost none of those born before the cutoff date were vaccinated.

The researchers compared the dementia diagnosis rates of the two groups with an emphasis on individuals with birthdays just before and after the cutoff date. The study found that individuals that received the shingles vaccine were 20% less likely to be diagnosed with dementia over the next seven years. The protective effect was stronger for women than for men.