Recent research suggests that the shingles vaccine may provide benefits beyond preventing shingles itself, potentially lowering the risk of dementia and cardiovascular problems. One study published in JAMA examined older Australians eligible for the live-attenuated shingles vaccine, Zostavax, and found they had a 1.8% lower chance of developing dementia compared to those who did not receive the vaccine. Another study in the European Heart Journal observed South Korean adults vaccinated with Zostavax experienced a 23% reduced risk of major cardiovascular events, including heart attacks and heart failure.
Experts believe these benefits may stem from the vaccine’s ability to reduce inflammation, a common consequence of infections like shingles. Dr. Pascal Geldsetzer, an assistant professor at Stanford University, explained that vaccines often influence the immune system more broadly than just triggering antibodies, which can result in benefits against other diseases.
Shingles is caused by the reactivation of the varicella-zoster virus (VZV), the same virus responsible for chickenpox. After initial infection, the virus remains dormant in the nerves and can reactivate later in life, causing painful rashes. While chickenpox cases have drastically decreased due to vaccination, VZV persists in those who were previously infected. Factors like stress may trigger the virus’s reactivation, with older adults and immunocompromised individuals being at greater risk.
To prevent shingles, health authorities recommend vaccination for adults over 50 and for immunocompromised younger adults. Notably, the CDC currently endorses the Shingrix vaccine, which is different from Zostavax and has become the standard since 2020 due to its higher and longer-lasting effectiveness. The recent studies focused on Zostavax because Shingrix was not yet widely available in Australia and South Korea during the research periods.
In the Australian study, over 101,000 individuals averaging 63 years old were monitored for more than seven years. Researchers compared those eligible for the free vaccine program with those who were not, discovering a significantly lower incidence of dementia among vaccinated participants. Dr. Geldsetzer highlighted that this is among the first strong evidence suggesting a cause-and-effect relationship between shingles vaccination and dementia prevention, noting that the protective effect was even more substantial than many existing dementia treatments.
The connection between shingles and cognitive decline may be explained by the dormant virus causing inflammation and nerve damage in the brain over time. Preventing shingles could therefore reduce this risk. Supporting this, another study published in Nature found similar reductions in dementia among vaccinated individuals.
Following the dementia research, a large-scale South Korean study analyzed health data from 2.2 million adults, over a million of whom received the live shingles vaccine. This study showed a 26% lower risk of major cardiovascular events and heart failure in vaccinated people, with a 22% reduction in coronary heart disease. The protective effects were strongest two to three years post-vaccination and lasted up to eight years. Benefits were especially noticeable in men under 60, people with unhealthy lifestyles, low-income individuals, and rural residents.
Study author Dr. Kyeongmin Lee from Kyung Hee University Medical Center explained that vaccination might reduce inflammation and clot formation linked to shingles infections, which contribute to heart disease. Although this study cannot conclusively prove cause and effect, the findings suggest the vaccine’s ability to prevent shingles-related inflammation may lower cardiovascular risks.
While these findings are promising, it is important to note that the current standard vaccine in the U.S., Shingrix, differs from Zostavax used in the studies. Shingrix is a recombinant vaccine containing viral proteins but no live virus, and research shows it is highly effective—about 97% in adults aged 50 to 69 and 91% in those 70 and older. Experts believe Shingrix may provide equal or better protection against dementia and heart disease, though this requires further study.
Despite the benefits, CDC data from 2019 indicated only about 26% of adults over 50 have received any shingles vaccine, highlighting a need for increased awareness and vaccination uptake. These recent studies add to the growing understanding that vaccines can offer broader health protections, encouraging more people to consider shingles vaccination as part of their preventive healthcare.
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