Vaccines hold tantalizing promise in the fight against dementia
Over the past two centuries, vaccines were essential to prevent infectious diseases. The World Health Organization believes that Vaccination prevents between 3 million and 5 million dead per year from diseases like diphtheria, tetanus,, flumeasles and, more recently, COVID 19.
Although there have been a long time Large scientific consensus The fact that vaccines prevent or reduce the spread of infections, there are new research suggesting that the therapeutic impact could go beyond the prevention of infectious diseases.
An April 2025 study published in the prominent nature journal found enticing evidence that herpes zoster – or zonge – vaccine could reduce the risk of dementia in the general population of 20%.
We are a team of scientific doctors with expertise in the clinical And fundamental science neurodegenerative disorders and dementia.
We believe that this study potentially opens the door to other breakthroughs in the understanding and treatment of dementia and other degenerative disorders of the brain.
A role for vaccines in reducing the risk of dementia?
One of the main challenges facing the researchers when they try to study the effects of vaccines is to find an unaccompanied “control group” for comparison – a group that is similar to the vaccine group in all respects, except for the fact that they have not received the active vaccine. Indeed, it is contrary to ethics to allocate certain patients to the control group and to deprive them of protection against vaccines against a disease such as zona.
The study of nature took advantage of a change of policy in the land of Wales which entered into force in 2013, declaring that people born on September 2, 1933 or after were eligible for vaccination against herpes Zoster for at least a year, while those born before this deadline were not. The vaccine was administered to Prevent shinglesa painful condition caused by the same virus that causes chickenpox, which can remain dormant in the body And be reactivated later in life.
In relation: The zono vaccine
The researchers used the change of policy as a natural laboratory to study the effect of vaccination on zona on long -term health results. In a statistically sophisticated analysis of health files, the team found that the vaccine reduced the probability of obtaining a dementia of a fifth over a period of seven years. This means that people who received the zona vaccine were less likely to develop clinical dementia during the seven -year follow -up period, and women have benefited more than men.
The design of the study allowed researchers to compare two groups without actively depriving any access group for vaccination. The two groups also had a comparable age and had similar medical comorbidities – which means similar rates of other medical conditions such as diabetes or high blood pressure.
Results of this and Other related studies Make the possibility that vaccines can play a broader role in experimental therapies outside the field of infectious diseases.
These studies also raise provocative questions about the functioning of vaccines and how our immune system can potentially prevent dementia.
How vaccines could be protective
A scientific explanation for the reduction of dementia by the hepes zoster vaccine could be the direct protection against the shingles virus, which can play a role in the exacerbation of dementia.
However, it is also possible that the vaccine has given protection by activating the immune system and providing “Immunity formed“In which the immune system is reinforced by a repeated exposure to vaccines or viruses.
The study did not differentiate between different types of dementia, such as dementia due to Alzheimer’s disease or dementia due to a stroke. In addition, researchers cannot draw any definitive conclusion on the possible mechanisms of the way in which vaccines could be protective of an analysis of health files alone.
The next step would be a prospective, randomized, double -blind and controlled and controlled study by placebo – “the gold stallion” of medical trials in medicine – to examine directly how the hepes zoster vaccine compares to a placebo in their ability to reduce the risk of dementia over time. Such studies are necessary before vaccines, as well as other potential therapies, can be recommended for clinical routine use in dementia prevention.
Dementia’s challenges
Dementia is a major non -transmitted disease A main death cause in the world.
A January 2025 study provided Figures updated on the risk of dementia for life through different subsets of the American population. Researchers believe that the lifetime risk of dementia after the age of 55 is 42% – more than double previous estimates. The risk of dementia was 4% compared to 75 years and 20% at the age of 85, the majority of risks occurring after 85 years. Researchers have planned that the number of new cases of dementia in the United States would double over the next four decades, from around 514,000 cases in 2020 to 1 million in 2060.
Formerly considered a disease widely confined to the developed world, the demental effects of dementia are now obvious worldwide, as life expectancy increases in many developing countries in the past. Although there are different forms of dementia with variable clinical manifestations and an underlying neurobiology, Alzheimer’s disease is the most common.
Prospective studies that specifically test how to give a vaccine modify the risk of future dementia can benefit from the study of patient populations with specific types of dementia because each version of dementia may require separate treatments.
Unfortunately, during the last two to three decades, the AMYloid hypothesis of Alzheimer’s disease – which postulates that the accumulation of a protein called amyloid in the brain contributes to the disorder – dominated scientific conversation. As a result, most efforts in the experimental therapy of Alzheimer’s disease have focused on drugs that reduce amyloid levels in the brain.
However, the results to date have been modest and disappointing. THE Two recently approved hypochoid therapies have only one Minimal impact on the slowdown in the decreaseare expensive and have potentially serious side effects. And no medication currently approved by the Food and Drug Administration for opposite clinical use of cognitive decline.
Studies based on health files suggest that Anterior exposure to viruses increases the risk of dementiaWhile routine vaccines, including those against tetanus, diphtheria, darling, pneumonia, shingles and others, reduce.
Innovation and an open mind
Sometimes there is a tendency among scientists to cling to older and familiar disease models and a reluctance to move to more conventional directions.
However, the process of achieving science has a way to teach researchers like us humility, to open our minds to new information, to learn from our mistakes and to go where these data take us in our quest for effective and wild therapies.
Vaccines can be one of these less frequented paths. It is an exciting possibility that could open the door to other breakthroughs in the understanding and treatment of degenerative brain disorders.
This published article is republished from The conversation Under a creative communs license. Read it original article.
