V. Walker, A. L. Schaffer, W. J. Hulme, C. Wood, A. Tamborska, A. J. Walker, B. MacKenna, B. Goldacre, J. A. C. Sterne, P. A. C. Geldsetzer
The English national shingles vaccination programme was officially launched on 1 September 2013 using the live attenuated herpes zoster vaccine Zostavax and updated on 1 September 2023 to replace Zostavax with the two-dose, non-live, recombinant subunit herpes zoster vaccine Shingrix. A study using a regression discontinuity design, conducted following the introduction of the herpes zoster vaccination programme on 1 September 2013 in Wales and using the SAIL databank to analyse Welsh routinely collected data, suggested that Zostavax vaccination reduced the probability of a new dementia diagnosis by approximately 20% over a seven-year follow-up period. The effects of Zostavax and Shingrix on incident dementia in England have not been published to date. This protocol describes a regression discontinuity study to study the effect of herpes zoster vaccines on incident dementia in England using linked electronic health records from OpenSAFELY.