Dementia is a growing global public health concern, and a new meta-analysis published in a leading medical journal has found a link between influenza vaccination and a decreased risk of dementia. The study aimed to systematically examine the relationship between the two and was conducted by a team of international researchers. The findings were published in the Journal of Alzheimer’s Disease. 

The team conducted a comprehensive search of several databases, including PubMed, Embase, Web of Science, ScienceDirect, medRxiv, and bioRxiv, for studies investigating the relationship between dementia and influenza vaccination. The search covered a period up to September 14, 2022, and the results of six cohort studies were included in the final meta-analysis.

The study found that among the 2,087,195 participants without dementia at baseline (mean age: 61.8–75.5 years, 57.05% males), 149,804 (7.18%) developed dementia during the 4 to 13 years of follow-up. The pooled analysis of adjusted relative risks (RRs) found that influenza vaccination reduced the risk of dementia by 31% (RR = 0.69, 95% CI: 0.57–0.83). Subgroup analyses showed that the association between influenza vaccination and reduced dementia risk was generally weaker in studies with a mean age of 75–80 years or 75%–100% of male participants.

The results were found to be stable in sensitivity analyses and no evidence of publication bias was observed. The authors concluded that influenza vaccination in older adults was associated with a decreased risk of dementia and called for more studies to clarify the mechanism behind the association.

The study adds to the growing body of evidence highlighting the importance of influenza vaccination, not only for its primary purpose of preventing the flu but also for its potential to reduce the risk of other serious health problems, including dementia. The findings could have important implications for public health policies aimed at reducing the global burden of dementia.