Older adults who receive the herpes zoster (HZ), and tetanus, diphtheria, pertussis (Tdap) vaccinations are less likely to develop Alzheimer’s disease, according to research by scientists at St. Louis University School of Medicine.
They examined medical claims data from more than 200,000 patients 65 years of age and older and found that receipt of either Tdap or HZ vaccination was associated with a significantly lower risk of incident dementia. Patients who received both vaccinations compared with none had a 50% lower risk for dementia and were significantly less likely to develop dementia as compared with those who received only Tdap or only HZ vaccination.
Study results suggest a common pathway may underlie the association between vaccines and dementia risk, the authors noted.
“Although speculative, repeated vaccinations may train the immune system and lower the risk for chronic inflammation, increasing appropriate immune responses and the body’s ability to resist bacterial and viral threats,” they wrote.
Full findings were published in the Journal of the American Geriatrics Society.