Flu and pneumonia vaccination are linked to significantly lower rates of Alzheimer’s, according to studies presented this week at the Alzheimer’s Association Conference 2020. 

A single flu vaccination is tied to a 17% reduction in Alzheimer’s incidence, and more frequent flu vaccinations confer an additional 13% risk reduction, scientists at the University of Texas have found. The effect was strongest for those who got their first flu shot at a younger age (age 60 versus 70, for example).

For adults between the ages of 75 and 84, consistent vaccinations translate to an approximately 6% reduced risk of Alzheimer’s disease over a 16-year period, the researchers added.

Meanwhile, a Duke University study of pneumococcal vaccinations found similar associations. Getting a pneumonia shot resulted in up to 30% lower Alzheimer’s risk for people between the ages of 65 and 75. The largest risk reduction — up to 40% — was observed among older adults who were vaccinated against pneumonia and who did not carry a gene linked to Alzheimer’s. The association with lowered risk was not evident for the flu shot alone, however.

Although the two studies do not determine causation, the link between vaccination and Alzheimer’s may have lifestyle implications, remarked Maria C. Carrillo, Ph.D., Alzheimer’s Association chief science officer.

“It may turn out to be as simple as if you’re taking care of your health in this way — getting vaccinated — you’re also taking care of yourself in other ways, and these things add up to lower risk of Alzheimer’s and other dementias,” Carrillo said.