Routine Vaccines May Help Cut Dementia Risk: Studies

A growing body of research suggests that several common vaccines may do more than just prevent infectious diseases—they're also linked to a lower risk of developing dementia. Physicians and researchers point to this as an added incentive for adults, especially older ones, to keep up with routine vaccinations, reports the Washington Post.

• Flu vaccine: Multiple studies show a connection between getting a flu shot and a reduced risk of Alzheimer's and other forms of dementia. A 2022 analysis of more than 1.8 million seniors found those who got at least one flu vaccine were 40% less likely to develop Alzheimer's over the next four years than those who hadn't. Another study, in 2024, saw a 17% reduction in dementia risk among recipients.

• Shingles vaccine: There's also strong evidence for this vaccine. A study from earlier this year tracking 280,000 people in Wales linked the shingles vaccine to a 20% lower dementia risk over seven years. Similar results have been reported in Australia. The CDC recommends shingles vaccination for adults over 50 or those with weakened immune systems. (The shingles vaccine has also been found to have benefits for the heart.)
• RSV vaccine: Newly available as of 2023, this vaccine also been tied to decreased dementia risk. Recent data suggest that adults who received the RSV vaccine had lower rates of dementia over 18 months compared to those who got only the flu shot.
• How/why these vaccines are lowering dementia risk: The answer isn't entirely clear, but because certain infections, like the flu, have been tied to brain atrophy and dementia down the line, scientists speculate that getting vaccinated offers a protective measure by fending those illnesses off. A study from Harvard Health Publishing earlier this year noted that the shingles vaccine, for example, may bring down the inflammation that comes with infections, or even alter one's immune system to better protect against dementia. The Conversation notes that a "trained immunity" could come into play, in which repeated vaccinations and/or exposure to the illnesses themselves can bolster one's immune system.