A shingles vaccine seems to provide additional benefits
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Vaccination against herpes zoster, better known as shingles, not only helps prevent this painful infection; it also curbs the risk of cardiovascular problems.
A new observational study of more than a million people shows that those who received a single injection of the shingles vaccine Zostavax were 26 percent less likely to die from heart disease or experience a stroke, heart attack, or heart failure, compared to people who hadn’t been vaccinated, says Sooji Lee at Kyung Hee University.
“We know shingles causes inflammation in the blood vessels,” she says. “So by preventing the infection, the vaccine may also reduce the risk of cardiovascular disease.”
Shingles occurs when the varicella-zoster virus, which causes chickenpox and then stays in the body after symptoms clear up, becomes reactivated. This can happen at times when the immune system is weakened, such as during periods of stress or chemotherapy. Shingles causes a painful rash, which can sometimes get infected or scar.
Although cardiovascular events are not typically listed as complications of shingles, scientists now know that shingles is linked to about a 30 percent greater risk of stroke and a 10 percent greater risk of heart attack, especially within the first year of infection.
To see if vaccination mitigated this problem, Lee and her colleagues gathered data on 1,271,922 people aged 50 or older, collected between 2012 and 2024 by national health registries in South Korea. The researchers determined whether each person had received a live shingles vaccine or not and compared that to their later development of any of 18 types of cardiovascular disease, such as heart failure, stroke, thrombosis, arrhythmias and ischaemia. The team also investigated other health-related factors like age, sex, socioeconomic status, exercise levels and social habits.
Over an average follow-up period of six years, the risk of cardiovascular events after vaccination was 23 percent lower compared to the risk for unvaccinated people, Lee says.
Risks were even more reduced in men – with vaccination associated with a 27 percent drop in risk compared to only a 20 percent drop for women – and in people younger than 60, also with a 27 percent decreased risk compared to 16 percent in older people. Rural residents had a 25 per cent reduction versus 20 per cent for people in urban areas, and individuals with low income showed a 26 per cent drop compared to 20 per cent in higher earners. As for people with obesity, their reduction in risk decreased as BMI increased.
For specific cardiovascular events, vaccinated people were 26 percent less likely to have a stroke, heart attack or heart failure, and they were also 26 percent less likely to die from heart disease. The risk of coronary artery disease, meanwhile, dropped 22 percent.
Benefits were most pronounced two to three years after vaccination, then gradually diminished over the next five years.
The study “strengthens our confidence” that shingles vaccinations cut cardiovascular risks, probably by curbing the vascular inflammation caused by the zoster virus, says Galen Foulke at the Pennsylvania State University.
“Zoster itself has high morbidity from pain and post-herpetic neuralgia – a painful condition that can last years after shingles eruption,” he says. “But health systems around the world could find enormous healthcare savings through reduction of cardiovascular morbidity by investing in the relatively inexpensive zoster vaccine.”
Although more research is needed, the scientists suspect the vaccine helps reduce cardiovascular risks indirectly because it prevents shingles, which can damage blood vessels and provoke clot formation and inflammation, Lee explains.
The researchers focused first on the live-virus vaccine Zostavax rather than the newer recombinant vaccine, Shingrix – which contains just a viral protein rather than the virus itself – because Zostavax has been available for longer, which means there is more long-term data about its effects. Now they are turning their attention to Shingrix.
“Because it’s more effective at preventing shingles, we think the recombinant vaccine may offer even stronger cardiovascular protection,” says Lee.
While the study design doesn’t prove cause and effect like a randomized trial could, it does allow researchers to identify risk associations across large populations. Such large-scale data can reveal risk patterns that clinical trials might miss, Lee explains.
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