NEW DELHI: A new study has found that the shingles vaccine Shingrix may reduce the risk of major cardiovascular diseases, including coronary heart disease, heart failure and stroke, compared with the older shingles vaccine.
The study, published in the journal Nature Medicine, found that Shingrix was associated with a 9% reduction in overall cardiovascular disease risk during the seven years after vaccination. It also reported a 10% reduction in coronary heart disease and a 12% reduction in heart failure.
Shingles is caused by the Herpes zoster virus, which can reactivate in people who have previously had chickenpox. The older shingles vaccine, Zostavax, was introduced in 2006 but has since been replaced by Shingrix in countries including the UK and the US.
Researchers from the University of Oxford analysed electronic health records from more than 70,000 adults aged 60 and above using the US TriNetX database. The switch from Zostavax to Shingrix in October 2017 allowed researchers to compare long-term cardiovascular outcomes in people who received the two vaccines.
The study found that people vaccinated with Shingrix had a 9% lower overall cardiovascular disease burden than those who received Zostavax. Men who received Shingrix also had a 12% lower risk of stroke, while the risk of atrial fibrillation was 7% lower.
Researchers said the protective effects were seen in both men and women and were strongest in the years immediately after vaccination.
The Oxford team had earlier reported that Shingrix was also associated with a lower risk of dementia.
Dr Fabiana Corsi-Zuelli, who led the analysis, said: "Because we used a natural experiment created by the rapid switch between vaccines, our study addresses many of the biases of conventional cohort studies. However, a randomised clinical trial is needed to confirm that the vaccine truly protects the heart."
Dr Maxime Taquet, who led the study, said: "Having already shown that this vaccine is linked to a lower risk of dementia, we now find it may also protect the heart. If confirmed in clinical trials, vaccinating older adults against shingles could prevent hundreds of thousands of coronary heart diseases, strokes and cases of heart failure worldwide, making it one of the most impactful interventions we could offer to protect both the brain and the heart in later life."
Professor Paul Harrison said researchers are now trying to understand how the vaccine may protect the heart.
"A key question is, how does the vaccine produce its apparent benefit in protecting the heart? One possibility is that infection with the Herpes zoster virus might increase the risk of heart and vascular diseases, and therefore by inhibiting the virus the vaccine could reduce this risk. Alternatively, the vaccine also contains chemicals which might have separate beneficial effects on the heart."