IIf your doctor told you that there is a vaccine against you, can you take care of it? According to A to work Published in the magazine on April 2 Nature This question may no longer be hypothetical by researchers in the United States and Germany.
Varicella-zoster It is a virus of virus-science men who cause varici (suiçpox) in childhood and zoster (zona) after lying asleep in nerve cells and re-activating in later life. assumed It may cause a demans because it infects the nervous system. We have vaccinations against both conditions. The porching vaccine protects children from the first viral infection and a separate zone vaccine prevents the re -activation of the virus in previously infected adults (most adults born before the widespread Suiçifox vaccination began in the late 1990s), preventing the painful zone.
The traditional way to learn whether vaccination against adults against this virus will prevent the later periods of life will be a randomized controlled work. We take a group of adults and divide them into two randomly two groups: the “control” group that will not take vaccines and the “intervention” group that will receive vaccines. Then, over time we will see if there is a difference between the two groups. . problem Since the dementia was old age disease, we would have to closely follow thousands of patients who have collected health information for years – which is not a simple task.
The researchers behind this new study, including Markus Eyting and Pascal Geldsetzer of Stanford University, did not do any of them. They were smart enough to realize that this experiment had already happened – especially the accident – remained a mystery waiting to be revealed.
In 2013, the Wales Government decided that the adults born on September 2, 1933 or later decided that they will start to provide a zoster vaccine to avoid zone. Negative Be suitable. While a person born on September 4, 1933 could get vaccinated, on August 28, 1933, someone born just a week ago was not appropriate.
Read more: The new CDC work on vaccines and autism should adopt a radical approach
Since the definite week we were born, the Galli adults were born just before the slaughter and similar to each other, except whether they were suitable for vaccination. It was essentially randomized to get the zone vaccine.
A treatment is called a natural experiment of this phenomenon of patients who were mistakenly randomized – without any researcher guiding, “in the wild nature”. Natural experiments like this always take place, but researchers are often not noticed unless they remove them from the existing data.
Since many years of the launch of the vaccination program, researchers could look at the health records of Galli adults to see who has developed Dementia and who hasn’t done it since 2013. What they found was surprising.
Since they were not suitable, almost no one had a zone vaccine just before the slaughter. In the meantime, about half of those born immediately after the slaughter received vaccinations and accordingly, they had lower zone ratios (because the primary benefit of the vaccine is to reduce the risk of developing zone). However, surprisingly, the dementia diagnosis of those who are suitable for vaccination had the rate of dementia. The researchers estimated that there was a decrease of approximately 20% in the diagnosis of dementia.
This analysis is as remarkable, it does not tell us exactly From where The zone vaccine may have led to a lower diagnosis of dementia.
The most prominent explanation is that the re -activation of the virus during a zone section is prone to developing dementia and the re -activation of the vaccine reduces the risk of development of dementia. Researchers found evidence supporting this hypothesis. First, it had higher dementia rates with more zona attacks (and therefore more viral reactivation). Secondly, they found that antiviral drug fields for zone attacks – those who helped to close the activation of re -activation have lower dementia rates than those who do not receive antiviral drugs.
Read more: Why is the risk of alzheimer’s risk lower?
Another explanation may be something about the body’s response to the body that protects against the demans. Vaccines work by stimulating the immune system, and the immune response can theoretically affect the brain to reduce the risk of dementia. The researchers found two evidence showing that this could be a factor. First, when they received the Zona vaccines, they recently found that those who receive flu vaccines were more protected than those who only take the vaccine against demment. Secondly, they decided to look at the differences between men and women who showed different immune reactions to vaccines. (Can be women Stronger immune reactions more vaccination than men). They found that the protective effect against demans was much larger than men.
Any of these mechanisms may explain the potential protective effect of the zone vaccine against dementia. (One of us, Jena, investigated them in depth comment It was published Nature In addition to the study.
This progress in our understanding of the zoster vaccine, zona and dementia would not take place without realizing the conditions of a natural experiment in Wales, and without careful analyzing the data to understand what happened to these patients. In an age where data collects in almost every aspect of our lives, the emergence of natural experiments in health services is expected to be revealed as long as the researchers have the opportunity and resources to find and analyze them.
