Could a High-Dose Flu Shot Help Prevent Alzheimer's?

A new analysis of nearly 200,000 people age 65 and older found those who received a high‑dose flu vaccine had about a 55 percent lower risk of developing Alzheimer’s disease; the study’s authors say more research is needed to confirm the finding.

A new study reports that seniors who received a high‑dose influenza vaccine had a lower observed risk of developing Alzheimer’s disease. The analysis used data from nearly 200,000 people aged 65 and older. Earlier research from 2022 linked a standard flu shot with roughly a 40 percent lower risk, and separate 2025 research reported an association between the shingles vaccine and reduced dementia diagnoses. The Centers for Disease Control and Prevention recommends a stronger flu vaccine for people 65 and older for better protection against influenza. Key findings: - The recent analysis found an association between receipt of a high‑dose flu vaccine and about a 55 percent lower risk of Alzheimer’s in people 65 and older. - The study examined data from nearly 200,000 older adults. - A 2022 study led by Paul Schutz reported roughly a 40 percent lower Alzheimer’s risk after a standard flu shot for seniors. - A 2025 study reported a roughly 20 percent lower rate of dementia diagnoses over seven years after the shingles vaccine. - Authors note the cause of the associations is not established and propose theories such as reduced systemic inflammation and counteracting age‑related immune decline. Summary: If confirmed, the reported associations suggest vaccines could have broader effects on brain health and might offer a widely available preventive option. Undetermined at this time.