▎WuXiangEdited by Kant Content Team

"As we get older, our brains become less useful..." In our daily lives, we often hear our elders sigh like this, as if dementia is an inevitable result of aging. However, a recent study published in NatureNatureMedicineA study published in the journal JAMA reveals a surprising finding: vaccination against shingles is associated with a lower incidence of dementia.Clinical TrialsIt has been confirmed that the shingles vaccine may become an economical and effective means to prevent or delay dementia!

ShinglesIt is caused by the herpes zoster virus (also known as varicella zoster virus). It is estimated that almost all elderly people have this virus lurking in their nervous system. As we age, the ability of immune cells to fight infection gradually decreases, which also gives these viruses an opportunity to take advantage.Herpes zoster virusWhen the virus reactivates, blisters appear on the chest, abdomen or face, accompanied by excruciating pain. The shingles vaccine, Zostavax, has helped protect many people from shingles since it was first introduced in 2006. However, surprisingly, some studies have found that in addition to preventing shingles, the vaccine may also reduce the incidence of dementia.

A preprint paper (not yet peer-reviewed) published last June compared the incidence of dementia in people who received or did not receive Zostavax.The scientists found that vaccination led to about a fifth fewer new dementia diagnoses over a seven-year follow-up period.To confirm that this finding was not due to other confounding factors, the researchers conducted further analyses showing that shingles vaccination was only associated with a reduction in dementia, not any other common causes of death or disease; shingles vaccination did not lead to an increase in other vaccinations or preventive health measures. In addition, exploratory analysis results showed thatThe vaccine's protective effect against all-cause dementia and Alzheimer's disease is particularly significant among women.

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However, currentlyZostavaxIt has been discontinued in many countries and regions, including the United States.Currently, most people receive the herpes zoster recombinant protein vaccineShingrix。It is an inactivated subunit vaccine consisting of two parts, one of which isantigenGlycoproteinE（glycoproteinE),it is alsoShinglesAn important protein in viruses;The other part is calledAS01BAn adjuvant system that can bring about a strong and long-lasting immune response and overcome the decline in immunity that accompanies aging.

To determine the role of shingles vaccines in preventing dementia and whether this role differs between two different vaccines, Zostavax and Shingrix, scientists from the University of Oxford in the UK analyzed electronic health records (EHRs) in the United States.It includes data on more than 200,000 people who received one of the vaccines in the United States over the past decade.About half of them received Zostavax between October 2014 and September 2017, while the others received Shingrix between November 2017 and October 2020.

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Researchers examined the subjects after vaccinationSix-year health record, and compared the prevalence of dementia between the two groups. The analysis showed that individuals who received the Shingrix vaccine had a significantly reduced risk of dementia within six years. Specifically,Compared with the control vaccine, individuals who received the Shingrix vaccine spent 17% longer without a dementia diagnosis, equivalent to 164 days longer without dementia.This effect was consistent across multiple secondary analyses.Shingrix was also associated with a lower risk of dementia in individuals compared with two other vaccines commonly given to older adults: the flu shot and the tetanus/diphtheria/pertussis vaccine.It is worth mentioning that in this study, Shingrix was observed to have a dementia-preventing effect in both male and female individuals, but it was more significant in women.Vaccination prolonged the time without dementia diagnosis in males and females by 22% and 13%, respectively (P=0.017).

Dr Andrew Doig, Professor of Biochemistry at the University of Manchester, said:“This is a significant result, comparable in effectiveness to the recent study for Alzheimer's disease.AntibodyDrugs. Vaccination with a recombinant shingles vaccine may be a simple and inexpensive way to reduce the risk of Alzheimer's disease.”

More than 55 million people worldwide suffer from dementia, which is the seventh leading cause of death among older people worldwide.It is estimated that 1 in 3 people will develop dementia in their lifetime.Although recent drugs such as Eisai and Biogen's Leqembi (lecanemab) and Eli Lilly and Company's Kisunla (donanemab) have been approved by the U.S. FDA to help slow the progression of Alzheimer's disease, a common form of dementia, there is still no cure, making the prevention of dementia a high-profile public health issue.

The study published this time undoubtedly provides further evidence that shingles vaccination may be associated with a reduced risk of dementia, but as the study's corresponding author Professor Paul Harrison said,The study did not provide direct evidence that the shingles vaccine can delay the onset of dementia.There are still many scientists studying this issue. One possibility is thatActivation of the herpes zoster virus can trigger pathological changes that lead to dementia, so vaccination to prevent the activation of the herpes zoster virus can avoid the occurrence of dementia.Another possibility isAdjuvants, which are used in vaccines to enhance the immune response, play a role in the prevention of dementia.

In addition, because the current shingles vaccine is mainly given to the elderly, another question raised by the study is whether the prevention of dementia would be more effective if the shingles vaccine was given to younger people, or whether the vaccine would quickly become ineffective. Dr. Doig said that to answer this question, a randomized controlled clinical trial is needed to compare Alzheimer's patients who receive the vaccine with those who receive a placebo. Because the Alzheimer's disease process can begin decades before symptoms appear, he believes that dementia prevention may be more effective if the vaccine is given to people in their 40s or 50s.

We hope that the publication of this research result will trigger more related research and lead to more effective dementia treatments to benefit the majority of patients.

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