Recent scientific investigations have turned toward the potential neurological and cardiovascular impacts of the newer shingles vaccine, known commercially as Shingrix. Following earlier observations linking the newer shingles vaccine to lower dementia rates, researchers at the University of Oxford conducted a natural experiment to study vaccinated adults.
Oxford Researchers Analyze Shingles Vaccine and Neurological Risk
Shingles is a painful, often serious blistering skin rash caused by the varicella-zoster virus—the same virus that causes chickenpox in childhood—which can lead to lingering complications such as nerve damage, hearing and vision loss, and encephalitis. Health agencies recommend the shingles vaccine (Shingrix) for adults aged 50 and older.
The newer recombinant vaccine replaced an older live attenuated vaccine called Zostavax, which was discontinued in the United States in 2020 due to lower efficacy and rapid waning. To avoid healthy vaccine bias
—a confounding factor where people who regularly seek out vaccinations tend to be healthier overall—Oxford researchers utilized a natural experiment comparing similar groups of vaccinated individuals before and after the October 2017 approval of Shingrix in the U.S.
Study Design and Cognitive Findings
The research analyzed electronic health records from the TriNetX US Collaborative Network, which covers approximately 60 healthcare organizations and includes data from more than 100 million patients. According to womenshealthmag.com, investigators examined data from more than 200,000 people who received a shingles vaccine.
The analysis found at least a 17 percent reduction in diagnoses of dementia in the six years following administration of Shingrix, which translates to 164 or more days lived without a dementia diagnosis. Furthermore, individuals who received Shingrix demonstrated a 23 to 27 percent lower risk of developing dementia compared to those who received other vaccines. While the link appeared in both sexes, researchers noted that the effect was greater in women.
Lead study author Maxime Taquet, a lecturer in the Department of Psychiatry at the University of Oxford, noted that the size and nature of the study make the findings convincing. They support the hypothesis that vaccination against shingles might prevent dementia,
Taquet said in a statement, adding that if validated in clinical trials, these findings could have significant implications for older adults, health services, and public health.
Cardiovascular Outcomes and Ongoing Questions
In addition to neurological evaluations, the Oxford team examined cardiovascular outcomes over a seven-year period following vaccination. Researchers split 72,000 vaccinated individuals aged 60 and older into matched groups based on whether they received their shots six months before or six months after the new vaccine approval.
The study found that recipients of Shingrix experienced a 9 percent lower overall cardiovascular burden—defined as a combination of coronary heart disease, heart failure, and stroke—compared to those who received the discontinued Zostavax. Specific reductions included:
- 10 percent reduction in ischemic heart disease and coronary heart disease
- 12 percent reduction in heart failure
- 7 percent reduction in atrial fibrillation
- 12 percent lower chance of ischemic stroke among men
Despite these clear statistical associations, the biological mechanisms driving these protective effects remain unproven outside of randomized clinical trials. Alternatively, researchers theorize that reducing reactivations of the herpes zoster virus, or identifying a separate, unknown impact of the vaccine’s chemical composition on the brain and heart, could explain the results.
The study’s authors and independent reviewers emphasize that while the observational data are robust, clinical trials and mechanistic studies are required to confirm cause and effect.
Читайте также
