A Randomized, Placebo Controlled, Observer-blind, Phase IV Pragmatic Trial to Evaluate the Effect of Recombinant Zoster Vaccine on New Dementia Diagnosis in Adults Aged 76 Years or Older in Finland

What this Trial Is About

Researchers are evaluating the effect of the recombinant zoster vaccine on the risk of developing new dementia diagnoses among adults aged 76 years or older living in Finland. This phase IV pragmatic trial aims to assess whether receiving this vaccine influences the incidence of dementia, including Alzheimer's disease, over a long follow-up period. Participants will be randomly assigned to receive either the vaccine or a placebo. Participants in the vaccine group receive two doses of the recombinant zoster vaccine: the first dose on Day 1 and the second dose between 2 and 6 months later, following the approved dosing schedule. Those in the placebo group receive two doses of placebo injections on the same schedule. The study is randomized, placebo-controlled, and observer-blind to compare outcomes between these two groups. During the study, participants will be followed for up to 10 years after their first dose to monitor for new dementia diagnoses, death, or loss to follow-up. Researchers will use health register data to assess outcomes including new diagnoses of dementia and Alzheimer's disease. Safety monitoring includes exclusion of severely immunocompromised individuals and those living in nursing facilities. The total participation duration allows long-term observation of vaccine effects on dementia risk.

A Study to Evaluate the Effect of Recombinant Zoster Vaccine on New Diagnosis of Dementia in an Older Adult Population Aged 76 Years or Older in Finland