Researchers have found that the common shingles vaccination shows promising effects in reducing the risk of dementia, while it performs its primary task of shingles prevention. The shingles vaccine, originally developed to treat skin conditions caused by the varicella-zoster virus, has been demonstrated to reduce the risk of dementia while protecting against chickenpox.
Dementia affects 9 million Americans, causing progressive loss of memory and other cognitive abilities. The aging population is expected to double by 2060, making an urgent, efficient preventive strategy necessary.
Multiple studies suggest that individuals who had chickenpox in the past may develop shingles – a blistering and painful skin rash years later. The virus remains dormant in the nerve cells and can reactivate later. Shingrix, a recombinant shingles vaccine, is recommended for all adults starting at age 50 and individuals aged 19 and older with weakened immune systems.
Studies conducted during the last few years have shown that people who receive the shingles vaccine have a lower risk of developing dementia. The vaccination data from more than 300,000 older adults showed that dementia rates were low in vaccine recipients compared to those without vaccination. Further research involving over 200,000 individuals found that people who received the newer recombinant vaccine experienced a 164-day longer dementia-free life compared to those who had received the discontinued live vaccine.
A “natural experiment” conducted in Wales provides the most definitive evidence. In 2013, researchers capitalized on a birth-year-based eligibility policy for shingles vaccinations. Researchers analysed over 300,000 health records from seven years, demonstrating that dementia risk dropped by 20% or 3.5% for patients who received vaccinations.
Scientific evidence suggests biological mechanisms by which the shingles vaccine can reduce the risk of dementia, even though no definitive proof exists yet. The vaccine can reduce the harmful neurological and systemic inflammation caused by the virus. The vaccine can also boost cellular defense mechanisms that can help to protect brain tissue from degeneration. The reduced risk of stroke resulting from the shingles vaccines may reduce the risk of dementia indirectly.
The Shingrix vaccine is administered in 2 doses, given with an interval between 2 and 6 months. Research shows that this vaccine gives exceptional protection rates of 97% for adults between 50 and 69 years old and 91% for patients older than 70 years old. The vaccine also demonstrates long-term effectiveness. Research showed that people above 70 maintained high levels of immunity to shingles for at least 7 years. For immunocompromised adults, effectiveness ranges from 68 to 71% based on health conditions.
The Centers for Disease Control and Prevention (CDC) recommends Shingrix vaccination because of three specific criteria:
All adults aged 50 and older
Adults aged 19 and older with weakened immune systems
Shingrix has proven to be safe, but most recipients experience temporary and common side effects. The side effects are like pain in their arms, fatigue, headaches, and mild fever, which typically last for two to three days. The vaccine has shown a very rare potential link to Guillain-Barré syndrome, but this association remains exceptionally rare.
People with active shingles and pregnant women need to postpone the vaccination. People who have severe allergies to vaccine components should not get the vaccine.
Healthy living habits, like exercise and a balanced diet, will always protect against dementia, while medical experts anticipate adding shingles vaccination to this preventive approach. The preliminary study results require additional research to validate their findings while exploring potential long-term consequences.
Shingles vaccine is strongly recommended by healthcare providers due to its protective value against painful conditions and its potential to delay cognitive decline.
References:
- Shmerling RH. Can a routine vaccine prevent dementia? Shingles vaccination may come with unexpected benefits. Harvard Health Blog. April 29, 2025.https://www.health.harvard.edu/blog/can-a-routine-vaccine-prevent-dementia-202504293097
- Centers for Disease Control and Prevention. Shingles vaccination. CDC. Published July 19, 2024. Accessed April 28, 2025. https://www.cdc.gov/shingles/vaccines/index.html
