Shingles vaccine linked to lower dementia risk among older adults in nursing care

• An analysis of more than 500,000 Medicare beneficiaries highlights that older adults who received the recombinant shingles vaccine (RZV) had a lower risk of developing dementia than those who were not vaccinated.
• Vaccination was associated with a 24% relative reduction in dementia risk over 4 years, equating to an absolute risk reduction of approximately 6 percentage points compared with unvaccinated individuals.
• The protective association persisted after adjusting for a wide range of demographic and health factors, suggesting the findings were not solely explained by differences between vaccinated and unvaccinated groups.
• Although the study adds to growing evidence linking shingles vaccination to lower dementia risk, it does not prove cause and effect.

There has been increasing research in recent years exploring whether the shingles vaccine may offer benefits beyond protecting against herpes zoster (shingles), particularly in older adults, who are at higher risk for developing shingles.

One area attracting significant attention is the vaccine’s potential role in dementia prevention, with previous research suggesting it may lower dementia risk and slow disease progression for those already living with a dementia diagnosis.

Research conducted in Wales and Australia found that adults who received the older live-attenuated shingles vaccine, known as Zostavax, had a reduced risk of dementia. As of 2020, Zostavax is no longer available in the United States and was replaced by a newer recombinant zoster vaccine (RZV), known as Shingrix.

As such, researchers wanted to evaluate whether the newer RZV may also provide a protective benefit against dementia in older adults at high risk for the condition who were not up to date with shingles vaccination.

The findings, published in Annals of Internal Medicine alongside a patient summary, note that older adults admitted to skilled nursing facilities in the U.S. who received at least one dose of RZV had a lower likelihood of developing dementia during the following 4 years compared with those who remained unvaccinated.

This analysis adds to growing evidence that the shingles vaccine may offer benefits beyond preventing the painful viral condition, suggesting Shingrix could also be associated with a substantially lower risk of developing dementia.