A recent study has uncovered compelling evidence suggesting that getting vaccinated against shingles could lead to a 20% reduction in the risk of developing dementia over a span of seven years. This conclusion arises from a natural experiment conducted in Wales, where eligibility for the shingles vaccine was determined by individuals' birthdates. Employing advanced statistical methods often utilized in economics, researchers were able to isolate the impact of the shingles vaccine from other influencing factors, highlighting its potential role in safeguarding brain health as we age.
The study reveals that shingles vaccination is linked to a significant 20% lower risk of dementia diagnosis over a seven-year period. This finding emerges from a unique natural experiment designed to provide a causal analysis of vaccination effects. The research underscores the importance of routine immunization, not only for preventing shingles but also for its unexpected implications for brain health.
The research, led by Dr. Markus Eyting from Johannes Gutenberg University Mainz, capitalizes on the introduction of a shingles vaccination program in Wales initiated in 2013. Dr. Eyting and co-lead author Dr. Min Xie, from the Heidelberg Institute of Global Health, conducted a rigorous analysis using data from this program. “We applied our statistical expertise to medical data, bridging the gap between these two fields,” Dr. Eyting explained.
The study's design utilized a natural experiment framework, where vaccine eligibility was determined by an exact birthdate. Those born before September 2, 1933, were permanently ineligible for the vaccine, while individuals born on or after this date could receive it. This design allowed researchers to compare individuals who had just turned 80 with those who had not yet reached this age, ensuring that the only distinguishing factor was vaccination status. “This approach enables us to identify a causal effect rather than merely a correlation,” Eyting noted.
The researchers employed a regression discontinuity design, a method commonly used in economics, to establish a causal relationship between shingles vaccination and dementia risk. By focusing on individuals whose ages were just weeks apart, they could confidently assert that vaccination was the primary variable influencing the differences in dementia diagnoses. “Regression discontinuity analyses offer substantial opportunities for evaluating the effectiveness of public health measures,” Eyting added.
The study also involved contributions from Dr. Simon Heß of the Vienna University of Economics and Business, who provided expertise in econometric methodologies, as well as researchers from Stanford University. Dr. Eyting's work has garnered recognition, including the 2023 Young Economist Award from the European Economic Association for his research on discrimination causes.
These groundbreaking findings suggest that vaccination to prevent shingles may also play a crucial role in reducing the risk of dementia in later life. The study provides new insights into potential public health strategies aimed at combating dementia, emphasizing the need for greater awareness and implementation of routine immunization programs.
As the research continues to unfold, it highlights a promising direction in the fight against dementia, urging public health officials to consider the broader implications of vaccinations beyond their immediate protective effects. The study titled “A natural experiment on the effect of herpes zoster vaccination on dementia” represents a significant advancement in understanding the connection between vaccination and cognitive health.
