In June 2026, a new study published in Annals of Internal Medicine investigated whether vaccination against shingles (herpes zoster) could be associated with a reduced risk of dementia in older adults. Funded by GlaxoSmithKline, the team was comprised of researchers from Brown University School of Public Health and University of Delaware, who analysed data from over 500 000 adults ages 66 years and older who were admitted to a nursing facility between 2017 and 2022. With these adults not having dementia at the beginning of the study, the researchers compared those who had received at least one dose of the recombinant shingles vaccine within 12 months of admission with those who did not.
The team found that within 4 years, 18.8% of vaccinated participants developed dementia, compared to the 24.6% unvaccinated participants, corresponding to a 24% lower relative risk.
The authors caution that this study does not prove that the shingles vaccination is directly linked to dementia prevention as there are other differences between the groups which could affect the results. Additional research, including clinical trials, is recommended to confirm and better understand these findings.
More information about this study is available here: https://www.acpjournals.org/doi/10.7326/ANNALS-25-04689
