Shingles vaccination was linked to a lower risk of dementia among older adults in skilled-nursing facilities.This finding was in line with previous studies of older adults in other countries.The researchers cautioned that residual confounding, including healthy vaccinee bias, may have influenced outcomes.
Older adults at higher risk for dementia were less likely to have a dementia diagnosis if they received a herpes zoster (shingles) shot, a cohort study using target trial emulation showed.
Among 500,000 people in skilled-nursing facilities for post-acute or long-term care, those who received the recombinant zoster vaccine (Shingrix) had a 24% lower risk of being diagnosed with dementia over 4 years compared with those not vaccinated (risk ratio [RR] 0.76, 95% CI 0.69-0.84), reported Kaleen Hayes, PharmD, PhD, of the Brown University School of Public Health in Providence, Rhode Island, and co-authors.
Receiving at least one zoster shot was tied to a cumulative 4-year dementia risk that was 5.81 (95% CI 3.9-7.5) percentage points lower -- 18.8% versus 24.6% with no vaccine -- Hayes and colleagues wrote in Annals of Internal Medicine.
Earlier studies had suggested a link between shingles vaccination and a lower risk of dementia in older adults. Some of that research focused on the live-attenuated zoster vaccine (Zostavax), which is no longer available in the U.S. For example, a "natural experiment" in Wales found that people who received the live vaccine had a 20% lower risk of dementia.
