Scientists may have produced the strongest evidence to date that the zona vaccine is linked to a reduction in the risk of dementia.
Using health records of more than 280,000 elderly people in Wales, researchers found that those who had received the shingle vaccine were 20% less likely to develop dementia over the next seven years than those who have not received the vaccine.
The results, Posted Wednesday in the journal Nature, based on other recent studies that have demonstrated associations between herpes virus infections and an increased risk of developing dementia.
Main author Pascal Geldsetzer, Since the University of Stanford, said that the protective effects of the vaccine seemed to be “significantly more important” than those proposed by existing dementia drugs, but that additional research was necessary to determine whether the effects observed was really causal.
“If the zona vaccine prevents or really deleted dementia, it would be an extremely important conclusion for clinical medicine, population health and research on dementia,” said Geldsetzer.
According to researchers, there are two potential mechanisms that could explain how the areas of zones could reduce the risk of dementia, and they can even operate in tandem.
The first is that vaccination reduces the reactivations of the dormant chickenpox virus, which has proven to cause cognitive alteration and long-standing cerebral pathology similar to what is observed in Alzheimer’s disease.
The chickenpox virus, a type of herpes virus, causes chickenpox and can linger in the body for years, later reactivating as shingles.
“There is an growing set of research showing that viruses that preferentially target your nervous system and hibernate in your nervous system for a large part of your life can be involved in the development of dementia.”
Riverview Health Center, a Winnipeg hospital that is home to long-term patients, has created a space where patients with Alzheimer’s and dementia revive memories with objects from their past, such as a vintage living room dryer and an office space with an ancient typewriter. They also have a sensory room, a carpentry shop and a nursery.
The second possible mechanism is that vaccination triggers a more widespread immune response.
Tissa Wijeratne, a neurologist at RMIT University and Western Health who was not involved in research, said that the study was a “historic discovery” in brain health and disease prevention.
“It supports the emerging understanding that infections – in particular viruses such as chickenpox -zona – can contribute to long -term neurological decline.”
An “ingenious” natural experience
Although other studies have examined the link between vaccination of vaccination zones and the risk of dementia, it was difficult for researchers to disentangle the effects of the vaccine from the effects of other variables such as food and exercise, which can also influence the risk of dementia.
Randomized controlled trials are considered to be the ordeal to study causal relationships and can help eliminate these biases, but they are exceptionally expensive and with a high intensity of resources, especially over long periods.
To get around this, Geldsetzer and his colleagues Invoked on a great “natural” experience that could help them answer the question in the same way as a randomized controlled trial.
In 2013, Wales deployed the shingle vaccine for the elderly. But a jerks in the deployment meant that those who were 79 years old on September 1, 2013 were eligible to receive the vaccine for at least a year, while those who had already been 80 years old were not eligible for life.
“Just a difference of a week in this fraction of date of birth means that you essentially spend that no one is vaccinated about half of the population that is vaccinated,” said Geldsetzer.
Thanks to electronic health files nationally, the Researchers could Look at almost the entire population of Wales born between September 1925 and September 1942 to see how the status of vaccine affected the risk of dementia.
They focused their analysis on the closest people on each side of the vaccine eligibility threshold, so they were as close to the same age as possible.
Those who received the shingles vaccine were 3.5% less likely to have a global dementia, and 20% less likely to those who were not vaccinated.
“It was a really striking observation,” said Geldsetzer.
The research team also studied the impact of other variables, such as levels of education and the rates of other common health conditions, in both cohorts.
But they could not find any difference, apart from vaccination status, which would explain the amazing drop in dementia diagnoses.
“This is an ingenious use of registration and liaison data,” said Perminder Sachdev, a neuropsychiatrist from UNSW who focuses on dementia and has not been involved in the study.
“This is an example of the power of electronic files at the national level and the ability of researchers to link various health data sets.”
Researchers also found similar results in a second population, using electronic health files and the death of dementia from England.
Study the advantages of vaccines
Although the results, if they were confirmed by additional research, suggested vaccination could be an effective tool for preventing or degrading dementia, they also raised several questions.
To begin with, the study revealed that the risk of dementia reduces much more in women than men.
It is not a unique discovery to this study; Other studies on vaccination zones and the risk of dementia have also found that women seem to benefit more from the vaccine than men.
“We know that the effects of vaccines are stronger in women and that immunological responses to vaccines are different in men and women,” said Sachdev.
“We have to know more, including [about] Sexual differences in the pathogenesis of dementia in general. “”
Other studies have also been necessary to understand how vaccination could really give protection against dementia.
The research team specifically examined the live vaccine of the Zoster herpes – known as Zostavax – which was commonly used at the time.
Canadathe United Kingdom, the United States and Australia currently All recommend a different vaccine called Shingrix, which uses different technology, and is much more effective in protecting yourself from shingles.
“There has been proofs for some time since the elderly who receive their vaccinations in general are less likely to develop dementia. This is the best proof to date,” said Henry Brodaty, co -director of the Center for Healthy Brain Agging at the Unsw and which has not been involved in the study.
“Future research will determine whether the new Shingrix lift vaccine will provide the same advantage and if vaccination at a younger age can be just as effective.”
A big American study published last year found that Shingrix seemed to further reduce the risk of dementia in Zostavax.
The researchers of this study believe, however, that the living nature of the zostavax vaccine can have specific advantages to reduce the risk of dementia and hope to finance other clinical trials that studied them.
Although there is no proven prevention for dementia, doctors also recommend other stages of common sense to reduce risk. Stay socially and cognitively active. And control high high blood pressure and, for people with diabetes, high blood sugar, which are both linked to cognitive decline.
