With cold and flu season right around the corner, you may be thinking about eating better, exercising, or taking supplements to stay healthy. The flu shot and other vaccines—such as those for RSV, pneumonia, and shingles—go a long way in preventing serious illness. But what if rolling up your sleeve could also protect your brain and memory?  

This may just be the case. New research suggests routine vaccines may also reduce the risk of dementia and Alzheimer’s disease—providing hope for millions in the U.S. and their caregivers.  

Although a direct link between viruses, infections, and increased risk of Alzheimer’s hasn’t been proven, research shows they may be connected. And vaccines could reduce that risk of dementia. Here’s a look at some of the emerging research. 

Influenza and Pneumonia Vaccines 

Research presented at the Alzheimer’s Association International Conference in 2020 showed that receiving at least one flu vaccine was associated with a 17% reduction in Alzheimer’s disease. And more frequent vaccinations were tied to an additional 13% lower incidence.  

A second study presented at the conference found that people who were vaccinated against pneumonia between the ages of 65 and 75 had a reduced risk of Alzheimer’s by up to 40% (dependent on whether they were carriers of the ApoE4 gene).  

An additional study, in Journal of Alzheimer’s Disease, among nearly 936,000 people age 65+ found that those who received at least one flu vaccine were 40% less likely to develop Alzheimer’s disease than those who were unvaccinated.  

Experts say it’s unclear how vaccines may prevent Alzheimer’s, but there are some theories. For example, vaccines prevent illness that may cause brain inflammation. And the cumulative effect of the infections and inflammation can negatively affect cognitive ability. Another theory is that vaccines improve the immune system’s ability to clear amyloid, a protein found in elevated levels in those with Alzheimer’s. 

Shingles Vaccines 

Some studies show that having shingles can increase the risk of dementia, which has led researchers to investigate the likelihood that preventing shingles with the vaccine may also reduce an individual’s risk for dementia. 

In fact, a recent study in the journal Nature looked at the health records of more than 280,000 older adults. The study found those who received the shingles vaccine were 20% less likely to develop dementia over the next seven years compared to those who did not receive the vaccine. The study also showed that women were much more likely than men to be protected.  

Another 2024 study of more than 200,000 older adults compared an older shingles vaccine, which is no longer used, to a newer shingles vaccine. The risk of dementia was lower 6 years after receiving either vaccine, but those with the newer vaccine spent 164 additional days living without dementia. Researchers suggest this may be due to reduced inflammation, reduced risk of stroke, and a positive effect on immune function. 

RSV Vaccines 

In a recent study in the journal npj Vaccines, researchers analyzed the health records of over 430,000 people. They looked at two vaccines: Arexvy, which protects against respiratory syncytial virus (RSV), and Shingrix, the vaccine for shingles. Both vaccines contain the same adjuvant, an ingredient added to boost the vaccine’s effectiveness 

The study found both vaccines to be similarly effective in reducing dementia risk compared to the flu vaccine, which does not contain an adjuvant,. The Arexvy vaccine was associated with a 29% reduction in dementia risk in the following 18 months, and the results were similar for men and women. While it’s not clear how the RSV vaccine may help reduce the risk of dementia, studies show that the adjuvant stimulates cells of the immune system, which could help protect the brain from dementia.   

Other Vaccines  

Researchers have also explored other vaccines and their effect on reducing the risk of dementia and Alzheimer’s. For example, a 2025 study from the Alzheimer’s Association found that—among 130 million people, including 1 million with dementia—four vaccines lowered the risk of dementia: hepatitis A, typhoid, combined hepatitis A and typhoid vaccine, and diphtheria.  

While research exploring the link between certain vaccines and a reduced risk for dementia is continuing to come into focus, vaccines are still an important tool to prevent infections and keep older adults healthy, particularly those with chronic diseases. For example, the flu vaccine has been shown to reduce overall risk of illness by 50%.*  

However, despite the benefits of vaccines, research shows uptake has been declining for certain vaccines. In fact, a 2024 AARP survey found that nearly half of adults who are recommended to get the respiratory syncytial virus (RSV) vaccine aren’t likely to opt in. Less than optimal vaccination rates are attributed to several issues, such as access, awareness, insurance coverage, vaccine hesitancy, and misinformation.   

It’s important to speak with your doctor or pharmacist about what vaccines you may need. If you plan to travel, you may need to receive certain vaccines. There are also some new options, such as the FluMist nasal spray flu vaccine that can be delivered and administered at home. For more information or to find a nearby provider, contact your local health department or visit Vaccines.gov. 

To learn about current clinical trials at Charter Research, call Charter Research at 407-337-3000 (Orlando), 352-441-2000 (The Villages), or 773-300-1000 (Chicago). You can also fill out the form on this page, and one of our representatives will call you within 24 hours (excluding weekends). 

*In seasons when the flu vaccine strains are well-matched to circulating strains.