A new study published in journal Nature, titled A Natural Experiment On The Effect Of Herpes Zoster Vaccination On Dementia, has found that getting vaccinated against shingles, which is a painful rash caused by the reactivation of the varicella-zoster virus could also lower the risk of developing dementia later in life. This finding adds to the growing evidence that show that some viral infections could play a role in long-term brain health.Why Is Shingles Connected To Dementia?Shingles is caused by the varicella-zoster virus, the same virus that also causes chickenpox in the childhood. Studies have shown that once someone is cured from chickenpox, the virus stays dormant in their body and can then reactivate as shingles. It could be reactivate years later, or even decades later. This happens especially when the immune system weakens with age. Shingles can cause burning pain, tingling, blisters, and nerve damage that may linger.In recent years, scientists have started to look at the wider effects of viral infections, including their link to brain health. Since shingles affects the nervous system, researchers began wondering whether the virus might be involved in cognitive decline.How Was The Study Conducted?To find the connection between shingles and dementia, a team of researchers analyzed the health records of 280,000 people in Wales who were between the ages of 71 and 88 when a shingles vaccine program began in 2013. Due to vaccine supply limits, only people who were exactly 79 years old when the program launched were eligible to receive the vaccine. This created a natural comparison between people who got the vaccine and those just slightly older who did not.The study continued for next 7 years. It was found that those who received the vaccine had a 20% lower chance to be diagnosed with dementia. The researchers carefully ruled out other factors, such as differences in lifestyle or healthcare use, making the results especially strong.How Does A Vaccine For Viral Infection Protect One's Brain?As per experts, there are two ways this could be explained:(i) One of the first theories is that by preventing shingles, the vaccine reduces inflammation in the nerve and also in the brain. This chronic inflammation is what is being linked with many conditions including Alzheimer's and other forms of dementia.(ii) The other theory talks about how vaccine boosts the immune system. While generally it may help the body better protect the brain and other threats, the study noticed that women who have a stronger immune response gained more protection than men. In fact, this seemed to help those with autoimmune conditions and allergies.Which Vaccine Should You Choose?The vaccine used in the Wales study was Zostavax, an older version that is no longer in use in the U.S. It has since been replaced by Shingrix, which is more effective and longer lasting. Another study suggests that Shingrix may provide even stronger protection against dementia.While vaccines are not a guaranteed way to prevent dementia, these findings suggest they could be an important tool in reducing risk—especially at a time when few other options exist. Further studies are needed, but experts say the evidence is strong enough to consider shingles vaccines not just for protecting against painful rashes, but also for supporting long-term brain health.