Tdap vaccination tied to lower dementia risk in older adults

Tetanus, diphtheria, pertussis (Tdap) vaccination in older adults is associated with a 42 percent lower dementia risk, according to a study recently published in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences.

Jeffrey F. Scherrer, Ph.D., from Saint Louis University, and colleagues assessed whether Tdap vaccination is associated with incident dementia. The analysis included a Veterans Health Affairs (VHA) cohort (96 percent male; 91.2 percent White) and a MarketScan medical claims cohort of older adults (65.4 percent female) free of dementia for two years before the index period (2011 or 2012), with follow-up through 2018.

The researchers found that after controlling for confounding variables, patients with Tdap vaccination had a significantly lower risk for dementia in both cohorts (VHA: hazard ratio, 0.58; MarketScan: hazard ratio, 0.58) compared with older adults without Tdap vaccination.

"Several vaccine types are linked to decreased dementia risk, suggesting that these associations are due to nonspecific effects on inflammation rather than vaccine-induced pathogen-specific protective effects," the authors write.