There’s one simple, fast, and widely available treatment that could significantly lower the risk of Alzheimer’s in people 65 and older, according to a new study.
Researchers found that seniors who received a high-dose flu vaccine (four times stronger than the standard dose) had a nearly 55 percent lower risk of developing the cognitive disorder. We’re taking a deep dive into this promising research — and the growing body of evidence that other vaccines may also protect the brain from decline.
Flu vaccines and Alzheimer’s prevention
Back in 2022, a team led by Paul Schutz, MD, a professor neurology at at McGovern Medical School at UTHealth Houston, found that seniors who’d gotten a standard flu shot had cut their risk of developing Alzheimer’s by about 40 percent.
After their findings were published, Dr. Schutz was approached by officials at the public health department, who “asked if there was a difference with different dosages,” Dr. Schutz said in a news release. “I was confused.”
The CDC recommends that people 65 and older get the stronger flu vaccine, because their immune systems are typically less effective at fending off infections.
“I was stunned that, as a physician, I didn't know a higher dose was offered,” Dr. Schutz said.
His team then set off to investigate how the stronger shot could impact Alzheimer’s risk. They analyzed data from nearly 200,000 people 65 and older and saw that those who got the more potent jab had a 55 percent lower risk — and women seemed to benefit more.
Vaccines and brain health
Vaccines and their potential to protect the brain from cognitive decline is a growing area of interest. A few tantalizing studies that have recently shown the shingles shot could be particularly effective. An April 2025 study found that the jab appeared to prevent or delay dementia diagnoses by 20 percent over a seven-year period. And like the flu vaccine, the protective effect appeared to be stronger among women.
It’s not clear what’s driving this benefit. One theory posits that these shots are boosting the immune system and counteracting immunosenescence — the natural dampening of the body’s immunity as it ages — while also combating inflammation. Chronic inflammation is thought to damage brain cells and has been linked to tau pathology, the abnormal accumulation of the tau protein in the brain, which is considered a hallmark of Alzheimer’s.
“Enhanced [flu vaccines] confer greater protection against influenza infection, thereby decreasing risk of severe illness and the associated systemic inflammation that can promote neuroinflammation and neurodegeneration,” the authors of the recent study wrote.
More research is needed to determine what could be driving this. But if it does prove out that vaccinations can help prevent dementia, that would give clinicians a powerful, widely available prophylactic against a disease that impacts millions of Americans.
