The recombinant shingles vaccine is associated with lower risk of dementia

Emerging evidence suggests live herpes zoster (shingles) vaccination may protect against dementia, but most prior data focus on the live vaccine, which has been replaced by a recombinant vaccine in the United States and many countries. Using a natural experiment created by the rapid transition from live to recombinant shingles vaccines after October 2017, we compared dementia risk between vaccine types in U.S. electronic health records. Receiving the recombinant vaccine was associated with a significantly lower risk of dementia within 6 years post-vaccination, corresponding to a 17% increase in diagnosis-free time and 164 additional days lived without a dementia diagnosis among those subsequently affected. The recombinant vaccine also showed lower dementia risks than influenza and tetanus-diphtheria-pertussis (Tdap) vaccines. Effects were robust across multiple secondary analyses and present in both sexes, with a larger effect in women. These findings motivate mechanistic studies and support the rationale for a randomized controlled trial to confirm potential added benefits of the recombinant shingles vaccine.