Shingles vaccine may slow progression of dementia, new study suggests
A recent study reveals that the shingles vaccine not only protects against the painful viral infection but also potentially slows the progression of dementia. This two-dose shot, recommended for adults aged 50 and above in the United States, has shown promising results in reducing the risk of developing dementia and even slowing its progression among those already affected.
Shingles, caused by the varicella-zoster virus, is a painful rash that affects approximately one in three people in the U.S. during their lifetime. However, the risk of shingles and severe complications increases with age, making the shingles vaccine a crucial preventive measure for older adults.
The study, conducted by Dr. Pascal Geldsetzer and his colleagues, analyzed health records of older adults in Wales, where a shingles vaccination program was introduced in 2013. The program targeted adults in their 70s, with eligibility criteria based on age. The researchers found that receiving the shingles vaccine significantly reduced the probability of being newly diagnosed with dementia by 3.5 percentage points over seven years compared to those who did not receive the vaccine.
In the follow-up study, the same researchers examined data from over 282,500 adults in Wales, focusing on mild cognitive impairment diagnoses and dementia-related deaths among vaccinated and unvaccinated groups. The findings revealed a 3.1 percentage point reduction in the risk of mild cognitive impairment over nine years among those who received the shingles vaccine, with stronger protective effects observed in women.
Among older adults already living with dementia, the vaccine demonstrated a remarkable 29.5 percentage point reduction in the risk of dying from the disease over nine years. These results suggest that the shingles vaccine may play a crucial role in slowing the progression of dementia.
Dr. Geldsetzer proposed two potential mechanisms behind the vaccine's effects. Firstly, the virus causing shingles also causes chickenpox, remaining dormant in the nervous system. Even during hibernation, the virus interacts with the immune system, leading to inflammation in the nervous system, a key process in chronic diseases like dementia. Reducing viral reactivation through vaccination may benefit the dementia disease process.
Secondly, the vaccine boosts the immune system, strengthening its ability to fight infections. Research links various infections to increased dementia risk, so a robust immune system could help lower dementia risk.
Dr. Geldsetzer plans to raise funding for a randomized clinical trial to conclusively test the link between shingles vaccination and reduced dementia risks. The study's findings emphasize the shingles vaccine's potential to protect cognition from early to late stages of dementia, as supported by Dr. Angelina Sutin, a professor of behavioral sciences and social medicine.
However, Dr. Joel Salinas, a neurologist, notes that the findings may not apply to newer vaccines. While the study provides promising evidence, further research and replication are needed to establish a definitive connection between shingles vaccination and dementia risk reduction.
