The shingles vaccine currently in use, called ‘Shingrix’, is associated with a reduced risk of cardiovascular events – including heart attacks, heart failure and stroke – compared to the previous shingles vaccine, according to a major new study published in Nature Medicine.
Key findings:
- New evidence indicates that the current shingles vaccine (a ‘recombinant’ vaccine) reduces the risk of major cardiovascular events – including coronary heart disease, heart failure and stroke – compared to the previous shingles vaccine, adding to its previously reported benefits against shingles itself and against dementia.
- A study of more than 70,000 people by researchers at the University of Oxford, funded by the National Institute for Health and Care Research Biomedical Research Centre: Oxford Health (NIHR BRC: Oxford Health), found a 9% reduction in cardiovascular disease burden in the seven years after recombinant shingles vaccination, with a 10% reduction for coronary heart disease and a 12% reduction for heart failure.
- The benefit was seen in both sexes, and men also showed a lower risk of stroke.
- The findings suggest that the recombinant shingles vaccine may have additional value in terms of protection against cardiovascular disease. Further research, including clinical trials, is needed to confirm this, and to identify how and why the vaccine has this effect.
Shingles is a painful and serious condition afflicting many elderly people. It is caused by the Herpes zoster virus that can flare up in people who previously had chicken pox. A vaccine against shingles (Zostavax) has been introduced in 2006. In many countries, including the UK and USA, Zostavax has now been withdrawn and replaced by a much more effective ‘recombinant’ vaccine (Shingrix). In the UK, Shingrix is being offered by the NHS to all elderly people and certain other groups.
Several studies have suggested that vaccinated people may have a lower risk of cardiovascular disease. However, these studies compared vaccinated with unvaccinated people and their conclusions may therefore be biased because people who choose to be vaccinated differ from those who don’t.
In the new study, researchers at the University of Oxford and NIHR BRC: Oxford Health used the USA TriNetX electronic health records network. In the USA, there was a switchover between Zostavax and Shingrix in October 2017. This allowed the researchers to compare the risk of cardiovascular events over the following seven years in adults aged 60 and over who were vaccinated with Shingrix versus otherwise similar people who had received Zostavax. More than 36,000 people, matched for their characteristics, were in each group.
Shingrix was associated with a 9% lower overall burden of cardiovascular disease than Zostavax, including a 10% reduction for ischaemic heart disease and a 12% reduction for heart failure. Men who received Shingrix also had a 12% lower risk of stroke, and there was a 7% reduction in atrial fibrillation (irregular heart rhythm). The beneficial effects were present in both sexes and were strongest in the years soon after vaccination.
Various additional analyses showed that these findings are robust but the researchers say further research, including clinical trials, is needed before any suggestion is made that the shingles vaccine should be used to help prevent or delay cardiovascular disease. The same Oxford team previously showed that Shingrix is also associated with a lower risk of dementia.
Dr Fabiana Corsi-Zuelli, Postdoctoral Researcher in the Department of Psychiatry at Oxford, who led the analyses, 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, Associate Professor in the Department of Psychiatry at Oxford, 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.”Paul Harrison, Professor of Psychiatry and BRC: Oxford Health Theme lead for Molecular Targets, who co-led the study, said: “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.”
