Several previous studies have suggested that shingles vaccinations might reduce dementia risk, but most could not exclude the possibility that people who get vaccinated might have other dementia-protective characteristics, like healthier lifestyles, better diets or more years of education.

There have long been hints that certain viruses increase risk for later-in-life dementia, including the virus that causes chickenpox.

Researchers tracking dementia cases in UK adults have discovered the shingles vaccine could cut the risk of patients developing the disease.