April 5, 2026

@michaelokun

High-dose flu shot and Alzheimer’s risk: does more immune stimulation matter? Immunogenic means how strongly a vaccine activates the immune system. Bukhbinder and colleagues describe in a new paper in Neurology how high-dose vs standard-dose influenza vaccines relate to Alzheimer dementia risk in adults age 65 and older. Key Points: - High-dose influenza vaccination was associated w/ a lower risk of Alzheimer dementia compared to standard-dose vaccination over the follow-up period. - The reduction in risk appeared early and persisted for up to about 2 years, w/ a number needed to treat of roughly 185 at peak effect. - The benefit signal was stronger and more consistent in women compared to men. My take: This study adds to a growing body of evidence that vaccines may do more than prevent infections, they may also shape brain health. The difference between high-dose and standard-dose flu vaccines suggests that the magnitude of immune activation may matter. Importantly, recent data on the shingles vaccine has shown a signal for dementia risk reduction, reinforcing the idea that immune system training could influence neurodegeneration. We should be cautious, as this is observational data and not a randomized trial. Here are 5 points that resonated w/ me: 1- Vaccination may be an accessible tool we could use for brain health and dementia prevention. 2- Stronger immune responses from higher-dose vaccines may translate into greater protection beyond infection. 3- The consistent signal across multiple vaccine studies including influenza and zoster raises a potentially compelling biological hypothesis. 4- Sex differences may matter. Is it possible that women may derive greater cognitive protection from immune-based strategies? 5- Health care providers should consider the possibility of viewing some vaccinations not just as infection prevention, but as part of a broader brain health strategy. https://www.neurology.org/doi/pdf/10.1212/WNL.0000000000214782 #alzheimer #michaelokun #fixelinstitute