POS-2026-3003: The effect of herpes zoster vaccines on incident dementia in England

In 2013, England introduced a national vaccination programme to help protect older adults against shingles. The vaccine, Zostavax, was first offered to people aged 70 and 79, based strictly on their date of birth. Over the next few years, more age groups were included. In 2023, the programme was updated to use a newer vaccine, Shingrix, which is now offered to people turning 65 and 70, and to some adults with weakened immune systems.

Dementia is a condition that affects memory, thinking, and everyday functioning. It affects around 982,000 people in the UK and is one of the biggest health and care challenges facing older adults and their families. Caring for people with dementia places a large demand on the NHS and social care services.

A study in Wales found that people who received the original shingles vaccine (Zostavax) were less likely to be diagnosed with dementia over the following seven years. However, these results require confirmation in a larger dataset, such as is available in England. Further, we do not yet know if the newer shingles vaccine has a similar effect.

This project will use electronic health records from people in England to see whether those who were offered the shingles vaccine were less likely to develop dementia than those who were not eligible because they were born just after a certain date. By using this natural “cut-off” date, we can make fair comparisons. We will study both the older (Zostavax) and newer (Shingrix) vaccines. The results could help doctors and policymakers understand whether shingles vaccination might also help reduce the risk of dementia in later life.