BACKGROUND AND PURPOSE:

• Evidence suggests that the live herpes zoster (shingles) vaccine may reduce the risk of dementia in older patients
  • However, the live vaccine has been retired in the US and it is not known whether the recombinant vaccine may have the same effect
• Taquet et al. (Nature Medicine, 2024) compared the risk of dementia between vaccine types

METHODS:

• Propensity score matched retrospective cohort study
  • EHR data from the TriNetX US Collaborative Network
  • 62 healthcare organizations
  • >100 million patients 
• Population
  • Individuals in the US who received the shingles vaccine
• Exposures
  • Earlier cohort: Received first vaccine dose between 2014 and 2017
    • 98% live vaccine
  • Later cohort: received first vaccine dose between 2017 and 2020
    • 95% recombinant vaccine
• Primary outcome
  • Dementia

RESULTS:

• Earlier cohort: 103,837 individuals | Later cohort: 103,837 individuals
• Individuals in the group that predominantly received the recombinant vaccine were at a lower risk of developing dementia over the next 6 years compared to those that received the live vaccine
  • Restricted mean time lost (RMTL) ratio 0.83 (95% CI, 0.80 to 0.87) | P<0.0001
• The association was found consistently across dementia subcategories, except for frontotemporal and Lewy body dementia
• There was no difference in all-cause mortality
• Both shingles vaccines were associated with a lower risk of dementia than were the influenza and tetanus–diphtheria–pertussis vaccines
  • RMTL ratios 0.73 to 0.86 | All P<0.0001
• The effect was robust across multiple secondary analyses, and was present in both men and women but was greater in women

CONCLUSION:

• Receipt of the recombinant shingles vaccine is associated with a lower risk of dementia compared to those who received the live vaccine
• The authors state

Compared with the live vaccine, receiving the recombinant shingles vaccine is associated with a lower risk of developing dementia within the next 6 years

An increase by 17% in time lived without a dementia diagnosis (or 164 additional days among those later affected) is clinically meaningful and a particularly large effect size given that the live shingles vaccine is itself associated with a lower risk of dementia, as replicated here

Learn More – Primary Sources:

The recombinant shingles vaccine is associated with lower risk of dementia