Lay summary
Dementia is one of the most pressing health challenges facing New Zealand, particularly for Māori and Pacific peoples who experience higher rates and earlier onset. Current treatments are limited, and prevention strategies are urgently needed. Recent evidence shows that shingles (herpes zoster), especially when it affects the eye (herpes zoster ophthalmicus, HZO), may increase the risk of dementia. Promisingly, vaccination and antiviral medicines could reduce this risk, but we need to understand who is most at risk, when cognitive decline occurs, and how best to intervene. This project will follow people after HZO with detailed memory tests, eye imaging, blood tests and brain scans to detect early signs of damage and inflammation. By identifying critical pathways linking HZO to dementia, our research could lead to improved vaccination policy, better use of antivirals, and earlier detection of cognitive problems, helping reduce dementia's burden on individuals, whānau and the health system.