WASHINGTON (Dispatches) -- Researchers report that those who received at least one influenza vaccine were 40% less likely than their non-vaccinated peers to develop Alzheimer’s disease over the course of four years.
Scientists from the University of Texas Health Science Center at Houston compared the risk of Alzheimer’s disease incidence between patients with and without prior flu vaccination in a large nationwide sample of U.S. adults aged 65 and older.
They found that flu vaccination in older adults reduced the risk of developing Alzheimer’s disease for several years. The strength of this protective effect increased with the number of years that a person received an annual flu vaccine -- in other words, the rate of developing Alzheimer’s was lowest among those who consistently received the flu vaccine every year.
Future research should assess whether flu vaccination is also associated with the rate of symptom progression in patients who already have Alzheimer’s dementia.
Alzheimer’s disease affects more than 6 million people living in the U.S., with the number of affected individuals growing due to the nation’s aging population. Past studies have found a decreased risk of dementia associated with prior exposure to various adulthood vaccinations, including those for tetanus, polio, and herpes, in addition to the flu vaccine and others.