Not getting sick from the flu is reason enough to roll up your sleeve for a flu vaccine every fall. And along with preventing millions of cases of influenza each year, flu shots also reduce hospitalizations for complications of this misery-making seasonal illness, which are most common among older adults.
A 2021 study from researchers at the Centers for Disease Control and Prevention (CDC) found that adults who got vaccinated were 26 percent less likely to be admitted to the intensive care unit and 31 percent less likely to die from the flu compared to those who were unvaccinated. There seems to be protection from illness even when vaccines aren’t perfectly matched to the strain of flu virus circulating (which happens because the shot is formulated months in advance).
But evidence suggests other payoffs beyond defense from fever, fatigue, chills and aches.
“People don’t really appreciate the other potential benefits of flu shots,” says Michelle Barron, M.D., senior medical director of infection prevention and control for UCHealth in Aurora, Colorado. “It’s actually arming your immune system to fend off other problems.”
Here are four unexpected ways a flu vaccine can benefit the body and the brain.
1. A boost for the brain?
This study, published in the Journal of Alzheimer’s Disease, compared more than 47,000 people age 65 and older who were vaccinated against flu to a similar group of nearly 80,000 people who were not vaccinated. The findings: Those who got a flu shot were 40 percent less likely to develop Alzheimer’s disease over a four-year period.
“We weren’t actually expecting it to be that high,” says study coauthor Avram S. Bukhbinder, M.D., now a neurologist at Massachusetts General Hospital in Boston.