That Annual Flu Shot May Help Protect From More Than the Flu

More than 55 million people worldwide have been diagnosed with Alzheimer’s disease or other forms of dementia with a staggering 10 million new cases diagnosed each year. While the exact cause of Alzheimer’s remains unclear, new research suggests that the influenza vaccine may help guard against the disease.

The study followed nearly 1 million participants and found that those who were vaccinated against the flu at least once within a four-year period are 40 percent less likely to develop Alzheimer’s disease during that time. The study connects other vaccines, including tetanus, shingles, tuberculosis and diphtheria, to a decreased risk of Alzheimer’s.

There are a few potential theories as to why this vaccine can increase one’s protection against Alzheimer’s. One area of thought is that by preventing infection or reducing the severity of an influenza infection, the vaccine reduces the damage that the flu can cause to the brain, especially in those 65 and older. In addition, vaccines can alter the body’s immune response to the proteins linked to Alzheimer’s and other inflammatory responses that build up in the brain and kill the nerve cells or neurons around them.

The Centers for Disease Control and Prevention recently updated its official recommendation for the 2022-2023 flu season, and those 65 and older should get one of the stronger flu shots designed to give older adults more protection. There are currently three high-dose influenza vaccines recommended for those 65 and older that provide four times the antigen or immune triggers as standard dose flu vaccines.

While more research needs to be done and this study does not definitively prove that the flu vaccine itself protects against Alzheimer’s disease, there is substantial evidence to support a promising correlation.