The recombinant shingles vaccine is associated with lower risk of dementia.
Level 3 - non-randomized controlled study
Non-randomized comparative observational study / natural experiment using cohort data
PubMed 39053634 · doi:10.1038/s41591-024-03201-5
What was done
Researchers evaluated the risk of dementia following vaccination by leveraging the rapid transition from live to recombinant herpes zoster vaccines as a natural experiment. Dementia risk over 6 years post-vaccination was compared between individuals receiving the recombinant shingles vaccine and those receiving the live vaccine, as well as cohorts receiving influenza and tetanus-diphtheria-pertussis vaccines.
What was found
Receiving the recombinant shingles vaccine was associated with a statistically significant 17% increase in dementia diagnosis-free time over 6 years compared to the live vaccine, equating to 164 additional days lived without a dementia diagnosis among those who developed dementia. The recombinant vaccine was also associated with lower dementia risk compared to influenza and tetanus-diphtheria-pertussis vaccines. The association was present in both sexes but larger in women.
Why it matters
Because the live shingles vaccine has been largely phased out, these data provide evidence that the newer recombinant vaccine is also associated with reduced dementia risk, potentially more so than the previous formulation.
Limits
The abstract does not provide the sample size, specific demographic characteristics, or exact hazard ratios and confidence intervals. As an observational study rather than a randomized trial, residual confounding cannot be ruled out.