The short version
- A study of 70,000 adults found a 12 percent reduction in cardiovascular events within three and a half years of receiving the Shingrix vaccine.
- Researchers utilized a natural experiment comparing outcomes before and after the US switch from an older vaccine to Shingrix to minimize bias.
- While observational data is promising, experts emphasize that randomized controlled trials are necessary to definitively prove the causal link.
New research indicates that the widely used shingles vaccine may offer significant protection against heart attacks and strokes, potentially preventing thousands of deaths annually. The study, published in Nature Medicine, analyzed health records for 70,000 adults in the United States and found that individuals who received the two-dose Shingrix vaccine experienced a 12 percent lower risk of cardiovascular diagnoses during the three and a half years following immunization.
The findings suggest that the cardiovascular benefits of the vaccine could be comparable to those achieved by taking daily blood pressure-lowering medication. Dr. Maxime Taquet, a clinical lecturer at the University of Oxford who led the research, noted that if these results are confirmed through rigorous clinical trials, vaccinating older adults against shingles could prevent hundreds of thousands of cases of coronary heart disease, stroke, and heart failure globally. He described the potential impact as enormous for protecting both brain and heart health in later life.
Shingles is a painful condition caused by the reactivation of the varicella-zoster virus, which remains dormant in the body after a childhood chickenpox infection. The disease can cause severe rashes and nerve pain that may persist for months or years, a complication known as post-herpetic neuralgia. While the primary purpose of vaccination is to prevent this painful outbreak, emerging evidence points to broader systemic health benefits.
Previous studies had suggested a link between shingles vaccination and reduced cardiovascular risk, but those findings were often open to distortion because they simply compared vaccinated individuals with unvaccinated ones. This new research addressed that limitation by leveraging a natural experiment in the United States healthcare system. In 2017, there was a rapid transition from Zostavax, an older vaccine based on a weakened virus introduced in 2006, to Shingrix, which utilizes newer technology and is considered more effective.
By tracking health records over seven years, the researchers compared the incidence of cardiovascular disease in people vaccinated before and after this switch. The data showed that Shingrix was associated with a 12 percent reduction in major cardiovascular events, including heart attacks, heart failure, and stroke, within the first three and a half years. By the end of the follow-up period, the association remained but had diminished to a 4 percent lower risk.
Although the relative reduction appears modest, the absolute impact could be substantial given that heart disease and stroke remain leading causes of death worldwide. The researchers caution that while the observational evidence is strong, it does not prove causation. Several randomized controlled trials are currently underway to provide more definitive proof regarding whether recombinant vaccines like Shingrix offer superior cardiovascular protection compared to live virus vaccines.
Scientists are also investigating the biological mechanisms behind this potential protective effect. One hypothesis is that shingles infection itself increases the risk of heart and vascular diseases, meaning a more effective vaccine simply prevents this secondary damage. Alternatively, the vaccine may have broader effects on the immune system, suppressing inflammatory proteins that contribute to cardiovascular issues.
Independent experts acknowledge the quality of the evidence while maintaining scientific caution. Dr. Hugo Pedder, a research fellow in statistical modeling at the University of Bristol who was not involved in the study, stated that a randomized trial remains the gold standard for confidently answering whether recombinant vaccines provide these specific benefits. Until such trials are completed, he noted that this study offers some of the best-quality observational evidence supporting a positive effect on cardiovascular outcomes.
The implications of this research extend beyond individual health decisions to public health policy. If confirmed, the dual benefit of preventing shingles and reducing cardiovascular risk could strengthen arguments for widespread vaccination programs among older adults. However, until clinical trials validate these findings, medical professionals continue to recommend Shingrix primarily for its proven efficacy in preventing shingles and its associated complications.
As the scientific community awaits results from ongoing trials, this study adds to a growing body of literature exploring the intersection between infectious disease prevention and chronic health conditions. It highlights the potential for vaccines to offer benefits that extend far beyond their intended targets, suggesting that immune system modulation may play a critical role in long-term cardiovascular health.
Sources behind this briefing
Go to the original reporting
- The Guardian US↗Shingles vaccine linked to lower risk of heart attack and stroke, study finds
