Researchers here note a correlation between receiving influenza vaccination, even once, and the later risk of Alzheimer’s disease. This is interesting in the context of the present debate over the mechanisms of Alzheimer’s, particularly regarding whether or not persistent viral infection is an important driver of the condition. Inflammation and immune system dysfunction are also clearly important in the progression of neurodegenerative conditions. How exactly influenza vaccines might influence this complex decline is an open question. One might hypothesize that this is mediated by something other than biology – that people more likely to take care of their overall health, and thus have a lesser degree of chronic inflammation and lesser incidence of Alzheimer’s disease, are also more likely to make use of influenza vaccines.

People who received at least one flu vaccination were 17% less likely to get Alzheimer’s disease over the course of a lifetime, according to new research. “Because there are no treatments for Alzheimer’s disease, it is crucial that we find ways to prevent it and delay its onset. About 5.8 million people in the United States have this disease, so even a small reduction in risk can make a dramatic difference. We began our study by looking for ways we could reduce this risk.”

“Our role was to sort through enormous amounts of de-identified patient data in the Cerner Health Facts database to see whether there are drugs that could be repurposed to reduce the risk of Alzheimer’s disease. Once we identified the flu vaccine as a candidate, we used machine learning to analyze more than 310,000 health records to study the relationship between flu vaccination and Alzheimer’s disease.”

The research team also found that more frequent flu vaccination and receiving vaccination at younger ages were associated with even greater decreases in risk. “One of our theories of how the flu vaccine may work is that some of the proteins in the flu virus may train the body’s immune response to better protect against Alzheimer’s disease. Providing people with a flu vaccine may be a safe way to introduce those proteins that could help prepare the body to fight off the disease. Additional studies in large clinical trials are needed to explore whether the flu shot could serve as a valid public health strategy in the fight against this disease.”