Shingles vaccine tied to fewer dementia diagnoses, study in Wales suggests
New Evidence Suggests Shingles Vaccine May Reduce Dementia Risk
A groundbreaking new study has provided compelling evidence that the shingles vaccine may be linked to a reduced risk of developing dementia. Researchers analyzed the health records of over 280,000 older adults in Wales and found that those who received the shingles vaccine were 20 percent less likely to develop dementia over the next seven years compared to those who did not receive the vaccine. The findings, published in the prestigious journal Nature, add to a growing body of research that has identified connections between herpes virus infections and an increased risk of dementia.
Lead author Pascal Geldsetzer, from Stanford University, noted that the protective effects of the shingles vaccine appeared to be significantly greater than those offered by existing dementia medications. However, he emphasized the need for further research to confirm whether the observed effects were indeed causal. If proven true, the implications of the shingles vaccine in preventing or delaying dementia could be monumental for clinical medicine, public health, and dementia research.
The study proposed two potential mechanisms through which the shingles vaccine could reduce the risk of dementia, which may work in conjunction. Firstly, vaccination may decrease reactivations of the dormant varicella-zoster virus, which have been linked to long-lasting cognitive impairment and brain pathology similar to Alzheimer’s disease. Varicella-zoster virus, a type of herpes virus, causes chickenpox and can remain latent in the body for years before reactivating as shingles.
Secondly, vaccination could trigger a broader immune response in the body. Tissa Wijeratne, a neurologist at RMIT University and Western Health, hailed the study as a landmark finding in brain health and disease prevention, supporting the idea that infections, particularly viruses like varicella-zoster, may contribute to long-term neurological decline.
To address the challenge of disentangling the effects of the shingles vaccine from other variables that influence dementia risk, the researchers employed a large-scale, natural experiment in Wales. The rollout of the shingles vaccine in 2013 led to a unique situation where individuals born on specific dates were eligible for vaccination at different ages. By analyzing nationwide electronic health records, the researchers could compare dementia risk between vaccinated and unvaccinated individuals of similar ages.
The results showed a striking 3.5 percent reduction in dementia risk overall among those who received the shingles vaccine, with a significant 20 percent decrease compared to the unvaccinated group. The study’s innovative approach impressed experts like Perminder Sachdev, a neuropsychiatrist at UNSW, who underscored the power of nationwide electronic records in research.
While the findings hold promise for the potential benefits of vaccination in preventing dementia, questions remain, such as the observed gender differences in vaccine effectiveness and the specific mechanisms by which vaccination confers protection. Additionally, the study focused on the live herpes zoster vaccine Zostavax, while newer vaccines like Shingrix have shown greater efficacy against shingles.
Further research is needed to explore whether different vaccines offer similar dementia risk reduction and whether earlier immunization could be equally effective. Despite the absence of a proven prevention for dementia, experts recommend maintaining social and cognitive engagement, managing high blood pressure and blood sugar levels, and staying informed about emerging research on dementia risk factors.
As research continues to uncover the intricate connections between infectious diseases and neurological conditions like dementia, the potential role of vaccines in safeguarding brain health offers hope for a future where cognitive decline may be preventable.
