Recombinant zoster (Shingrix) to see if it lowers new dementia diagnoses in people 76 and older in Finland.

A Randomized, Placebo Controlled, Observer-blind, Phase IV Pragmatic Trial to Evaluate the Effect of Recombinant Zoster Vaccine (Shingrix) on Incident Dementia Diagnosis in an Older Adult Population Aged ≥76 Years in Finland

This trial will test whether the Shingrix shingles vaccine lowers the chance of a new dementia diagnosis in people aged 76 or older who live in Finland.

Quick facts

• Phase: Phase 4
• Study type: Interventional
• Enrollment: 33609 (estimated)
• Ages: 76 Years and up
• Sex: All
• Sponsor: GlaxoSmithKline (Industry-sponsored)
• Locations: 8 sites (Espoo and 7 other locations)
• Trial ID: NCT07502560 on ClinicalTrials.gov

What this trial studies

This Phase 4 randomized, placebo-controlled study enrolls Finnish adults aged 76 and older and randomizes them 3:1 to receive recombinant zoster vaccine (Shingrix) or placebo. Participants must be permanent residents of Finland without a prior dementia diagnosis or prior receipt of any herpes zoster vaccine and will provide consent to link their health register data. The primary outcome is occurrence of a new dementia diagnosis measured through Finnish health registers over follow-up after vaccination. As a post-licensure study sponsored by GlaxoSmithKline, it relies on registry-based outcomes to capture real-world diagnoses rather than intensive in-person cognitive testing.

Who should consider this trial

Good fit: Ideal candidates are Finnish residents aged 76 or older who have never received a herpes zoster vaccine, have no history of dementia, and can give informed consent including health register access.

Not a fit: People who already have a dementia diagnosis, have previously been vaccinated against herpes zoster, are younger than 76, or do not live in Finland are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, vaccination could lower the risk of new dementia diagnoses in older adults and provide an additional reason to use Shingrix beyond preventing shingles.

How similar studies have performed: Observational studies have reported associations between some vaccines (including zoster and influenza vaccines) and lower dementia risk, but randomized controlled evidence testing Shingrix for this outcome is limited, making this approach relatively novel.

Eligibility criteria

Inclusion Criteria:

* Citizens living permanently in Finland, who, in the opinion of the investigator, can and will comply with the requirements of the protocol.
* Written or witnessed informed consent obtained from the participant prior to performance of any study-specific procedure. Informed consent will include consent to access health register data for participants.
* Age 76 years or older at the time of signing the informed consent.

Exclusion Criteria:

* Prior receipt of a Herpes Zoster (HZ) vaccine.
* History of dementia diagnosis prior to enrolment, including confirmed cases or those under investigation. This includes:

  * History of a confirmed clinical diagnosis of dementia prior to enrolment.
  * Prior or current use of medications intended to treat dementia.
  * Current or recent history of cognitive assessments for any memory deficit or suspected dementia before enrolment including investigations that are ongoing or that were inconclusive (but not those for which dementia was conclusively ruled out); mild cognitive impairment on its own without any other information to indicate cognitive decline or dementia will not result in exclusion.
* Severely immunocompromised individuals.
* Concurrently participating in another clinical trial, in which the participant has been or will be exposed to an investigational product or ongoing participation in trials focused on preventive dementia interventions.
* Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccines used in the study or to a vaccine containing any of the same substances.
* Living in a nursing facility.

Where this trial is running

Espoo and 7 other locations

• GSK Investigational Site — Espoo, Finland (Recruiting)
• GSK Investigational Site — Helsinki, Finland (Recruiting)
• GSK Investigational Site — Jarvenpaa, Finland (Recruiting)
• GSK Investigational Site — Kokkola, Finland (Recruiting)
• GSK Investigational Site — Oulu, Finland (Recruiting)
• GSK Investigational Site — Seinäjoki, Finland (Recruiting)
• GSK Investigational Site — Tampere, Finland (Recruiting)
• GSK Investigational Site — Turku, Finland (Recruiting)

Study contacts

• Study coordinator: US GSK Clinical Trials Call Center

Conditions Herpes Zoster; Recombinant Zoster Vaccine; Shingrix; Incident dementia; Alzheimer's Disease; Older adults; Finland