Key Takeaway:
- Multiple studies suggest the shingles vaccine may lower dementia risk in older adults.
- Researchers believe preventing shingles-related brain inflammation may help protect cognitive health.
- Health experts encourage eligible adults age 50 and older to receive the recommended Shingrix vaccine.
Growing evidence from multiple international studies suggests the shingles vaccine may reduce the risk of dementia in older adults by preventing inflammation and other neurological damage linked to the virus, though researchers say more studies are needed to confirm the connection.
A study published June 16 in Annals of Internal Medicine found nursing home residents who received at least one shingles vaccine dose within a year of admission had a 5.8% lower risk of developing dementia over the following four years. The research analyzed health records from more than 509,000 U.S. adults ages 66 and older.
Lead author Kaley Hayes, associate director of pharmacoepidemiology at Brown University School of Public Health, said the findings exceeded expectations.
“That’s huge,” Hayes said, referring to the potential impact of preventing dementia through vaccination.
Large Studies Link Vaccination to Lower Dementia Risk
The latest findings add to similar research from Wales, Australia, and Canada, where studies involving hundreds of thousands of older adults also found modest reductions in dementia risk among people eligible for or receiving shingles vaccines.
Researchers estimate that as many as one in 17 dementia cases could potentially be prevented through shingles vaccination if the association proves causal.
Previous studies have also linked shingles infection itself to an increased risk of dementia. About 1 million Americans develop shingles each year, according to the U.S. Centers for Disease Control and Prevention. More than 99% of Americans born in 1980 or earlier have had chickenpox, leaving them vulnerable to shingles later in life.
Researchers Explore How Shingles Affects the Brain
Scientists believe the virus may contribute to brain damage by triggering inflammation and the buildup of amyloid and tau proteins associated with Alzheimer’s disease.
“When the brain is stressed or challenged with any kind of illness, underlying risks for dementia become more apparent,” said Dr. Jennifer Pauldurai, medical director of the Inova Brain Health and Memory Disorders Program.
Dr. Timothy Chang, an assistant professor of neurology at the University of California, Los Angeles, said the vaccine may also strengthen the immune system in ways that reduce harmful inflammation affecting the brain.
Researchers caution that the studies are observational and do not prove the vaccine directly prevents dementia. However, several investigations were designed to minimize bias by comparing people based on vaccine eligibility rather than personal health choices.
Experts Urge Eligible Adults to Get Vaccinated
The CDC recommends two doses of Shingrix for adults aged 50 and older, including those who previously received older shingles vaccines or have had shingles.
Despite the recommendation, vaccination rates remain relatively low. As of 2022, about one-third of U.S. adults age 50 and older and 43.8% of adults age 60 and older had received at least one shingles vaccine dose. Researchers also found lower vaccination rates among Black and Hispanic adults.
Ann Philbrick, a professor at the University of Minnesota College of Pharmacy, said the low vaccination rate among nursing home residents in the study was particularly concerning.
Experts emphasize that vaccination should complement, not replace, healthy lifestyle habits known to support brain health. While additional research is needed to establish cause and effect, they say the growing body of evidence offers another reason for eligible adults to consider shingles vaccination.
Visit Healthcare 360 Magazine For The Most Recent Information.
