The little killers: the virus that most of us carry, and that takes four years of our lives

Are there 'small killers', quieter and more insidious than the big ones, which bring the body to the same state of systemic exhaustion that is so common in old age, and exposes the body to the big and colorful killers?

Throughout the last century, human life expectancy has been gradually increasing. It is currently estimated that for every ten years that pass, life expectancy in the West increases by three years. The quality of life for old age also increases and improves immeasurably. Elderly people who are 75 years old today, have the strength and endurance of 60-year-olds who lived in the middle of the XNUMXth century. And people who today reach the age of sixty are no longer treated as elderly at all - they usually continue to work and function with considerable success.

And yet, we strive for more. We want to achieve a longer and better life. We strive to reach the biblical limit of one hundred and twenty years - and pass it in good health. This is an ambitious goal, but it may well be possible. Already today, the human species is a surprising exception out of all living organisms in nature, in terms of its longevity. Lifespan is usually determined by body weight: elephants reach a lifespan of seventy years; Cows live thirty years. Mice - only two years. If we rely on the weight of an average person, we should not live more than about 15 years - the lifespan of a sheep or a pig. But we are capable of more than that, and no one understands why, why, or what the 'natural' limit to longevity is. We just keep trying to keep finding it again and again - and skyrocket above and beyond.

The big killers... and the little ones

In the western world there are three main causes of death: heart disease (mainly manifested in heart attacks), diseases of the cerebral arteries (usually manifested in strokes) and cancer of all types. These are the big killers that end the lives of many of us every year. They are also defined as diseases of old age, because the older a person is, the greater the chance that he will get one of them, and that this illness will be the final shot of his life.

But are these the real killers? There is no doubt that they kill many of us when we reach old age, where the body's systems are not functioning well and are not able to deal well with these big troubles. But are there 'small killers', quieter and more insidious than the big ones, which bring the body to the same state of systemic exhaustion that is so common in old age, and exposes the body to the big and colorful killers?

Probably so. And if you're able to read this article, there's a good chance you carry at least one of them.

A wolf in the skin of a virus

If you live in one of the western countries, there is good reason to believe that you too have been infected with a virus known as cytomegalovirus, or CMV to its friends. This is a fairly routine virus from the herpes group. When it was first discovered, it was widely believed that it was only capable of harming tender babies. Because of this, it was treated as an innocent virus that does no harm to the adult body - a kind of necessary by-product of life, or a hitchhiker that most of us carry without being aware of its existence.

If he is really so innocent, why does he specifically hurt babies? The answer to this question was found when AIDS patients in the eighties and nineties began to develop a variety of unpleasant symptoms, such as blindness and bruises on the skin, as a result of infection with the same apparently innocent CMV. The immune system of AIDS patients is damaged during the disease, so it is not able to stop the spread of the virus, which is free to spread its harmful effect in the body. The young and inexperienced immune system of babies is also exposed to the virus for the same reason.

This means that CMV is not as innocent as it seems at first glance. If the immune system lowers its defenses even for a moment, it will take the opportunity to attack the human host. This is not a surprising conclusion. The human body is a petri dish and a wonderful growth test for bacteria, viruses and fungi of all kinds and species. He provides them with food, cells to host them, and even oxygen (for those of them who need it). And yet, as long as the immune system continues to function, we have nothing to worry about CMV at least...

Right?

Mistake.

The immune system protects us from pests that enter the body through 'targeted elimination' of the invaders. The white blood cells learn to recognize certain viruses by their surface pattern, just as we can recognize other people by their facial features. Every time a new pest enters the body, the immune system calls out young white blood cells and trains them to recognize the invader. From this moment until the day of the person's death, those cells will dedicate their lives to searching for and fighting every identical pest, whether it hides in the recesses of the deepest tissue in the body, or travels brazenly in the bloodstream - the Ayalon pathways of the body. Their commitment to duty is so great that they completely abandon any possibility of fighting other pests, and only look for the invaders they have learned to recognize.

A similar process also occurs when the CMV virus enters the body for the first time. An entire class of white blood cells is called into command and goes through a grueling training regimen during which it learns to recognize the virus and fight it successfully. Most of the invaders are eliminated, but a small part of them manages to survive and hide in the body for a long time. After a period of days or years, they will gather renewed courage, build up their strength and erupt again in an attempt to take control of the body. The immune system will send its highly trained commando squad of white blood cells into the area to take over the unsociable protest… only to find that they fail to detect the virus.

You see, he's mutated.

This is a known strategy of viruses of all kinds, including the flu and the HIV that causes AIDS. Many of them are able to mutate at high speed and change their surface route. They shorten the nose and lengthen the chin, shrink the cheeks and add wrinkles to the forehead. The white blood cells, the body's policemen, are no longer able to identify the criminal. They stand by, helpless, while the virus begins to take over more cells.

But the immune system does not kill nests. In a short time, 'captives' are collected from among the new viruses, and a whole new company of young white blood cells undergoes training that equips it to fight the new-old threat. After a few days, the new proliferation is also eliminated, and the body can go back to resting on its cells.

That is, he could have done this, if it weren't for the fact that there were again a number of CMV virions left (a virion is one unit of a virus) that managed to hide inside the cells, and in the not-too-distant future will break into the bloodstream again, wearing a very different clusteron than the one they flew before. And again, and again and again. This is the constant war of existence waged by the immune system in CMV - every year, if not every day.

Life is pain, princess

As a biologist, aware that life in nature is based on a predator-prey system, I find beauty in this system, which is designed to protect the body from the unexpected and develop new defenses as needed. But the incessant warfare takes its toll. The number of young white blood cells is not infinite, and the CMV's ability to mutate means that almost every day a whole new class of 'novices' is assigned and undergoes training that dedicates them to fighting in the particular mask that the virus wears that day. Department after department, company after company, are secreted from the large pool of young cells, until almost forty percent of all white blood cells in the body are specifically trained to attack the thousands of possible masks that CMV wears... and it is still able to develop and continue to challenge them.

All this wouldn't be so bad if CMV was the only virus in the neighborhood attacking the body. he is not. New parasites and pests invade our bodies every day, and the immune system has to allocate its attention to them as well, and some of its young white blood cells. It is hard to believe that CMV completely consumes the pool of available young cells, but there is no doubt that it contributes its part to the depletion of the stock, thus leaving the body more exposed to various diseases.

Throughout most of our lives we are completely unaware of the eternal war going on to keep us alive. We do not notice the death of billions - billions of tiny cells - that sacrifice themselves every day to preserve the integrity of the body. In fact, we have no way of even knowing that we have been infected with CMV without a blood test. Only in a statistical analysis can the small damages associated with CMV infection be found. And these, it turns out, are not small at all.

This is the conclusion reached by Phil Moss from the University of Birmingham, who for the past 18 years has followed the health status of more than five hundred people over the age of 65. Using blood tests, he discovered that seventy percent of them carry the CMV in their bodies. A brief statistical analysis performed around the data demonstrated that the CMV virus may be more devastating than previously thought, because the life expectancy of the carriers was four years shorter than the life expectancy of the healthy people. According to Alison Aiello, an epidemiologist who was interviewed by New Scientist magazine on the subject, a four-year decrease in life expectancy is roughly equivalent to the statistical effect of smoking or heavy drinking on life expectancy. Moss presented the data at the recent Immunology 2012 conference in Boston.

Why do carriers live fewer years than their peers? The answer explains why we were not aware of the devastating effect of CMV until now: the virus itself is not the cause of death. People don't clutch their chests, whisper "cytomegalovirus" and fall to the ground lifelessly. The virus does not stand up to the firing squad that ends life - it only exhausts the immune system, until it cannot function in old age. When the immune system does not function well, the person is more exposed to all the diseases around him that bite his health as well. This is a snowball effect that increases itself throughout life, and the result - as expected - was that the CMV carriers suffered a lower life expectancy and a poorer physical and mental condition compared to the non-carrier elderly.

The proof

So far this is a fine example of scientific research based on educated guesses and the statistics that support them. But the statistics can fool us. It can be assumed that dozens, if not hundreds, of different parameters that could affect the health of the elderly were tested in Phil Moss's research. Each of the parameters could - completely in the hands of chance - appear in the carriers with a particularly high frequency. The fact that the carriers tended to die younger, therefore, cannot be considered proof in itself of the damage caused by the CMV virus. To confirm the claim, we have to perform real experiments.

Phil Moss also understood the limitations of statistical research, and decided to test the matter in the laboratory. He could not infect humans with the CMV virus, so he contented himself with injecting the virus into six-week-old mice. He gave the mice time to mature, then treated some of them with an antiviral drug. The drug eliminated the CMV population in the mice's bodies, and the beneficial results were not long in coming: the mice that received drug treatment were more resistant to infectious diseases, and managed to maintain a high number of immune system cells.

The additional research strengthens the link between CMV carriers and damage to health and a decrease in quality and life expectancy. It also gives hope to those of us who have already been infected with the virus - that is, the majority of humanity in Western countries and probably in Israel as well - and may gain several more years of quality life if they receive treatment with antiviral drugs.

Vaccination and her in it

Treatment with antiviral drugs may eliminate the virus, it is true. Unfortunately, such treatment sometimes requires long months - or even years - of taking pills, to get rid of every last virion still running around in the body. This is not a realistic solution for most people. It is much better to think about a vaccine for CMV, which will be given to every soft baby born. But it is not yet available, and for a simple reason: we still do not understand how CMV spreads, multiplies or infects new people. It is a kind of black box for us, which we are still trying to find out how to deal with.

Despite the current dismal situation, medical science continues to march forward with vigor. New phenomena are discovered every day, and medical developments are not shy to follow them. It is likely that when the time comes - be it in ten years or in fifty years - an effective vaccine will be developed for the CMV virus, and will lead to the growth of a new generation 'who did not know Pharaoh'. The members of that generation will live longer, and will suffer less from diseases in their golden years.

This is a happy prediction. Not only because of the additional four years on average that will be added to the human lifespan, but mainly because another factor that prevents a person from realizing his full potential for a long and happy life will be identified and eliminated. This future success signals the continuation of the trend to extend human life. The more our medical knowledge and our understanding of the body advances, the more we will identify and protect our bodies from a larger and larger number of those pests, parasites and invaders that have hitched a ride in our bodies without considering its well-being. Each of them robs us of a few more minutes of life every day, and together - who knows how many years of life they take from us in a round.

It's time to pay.

This article is a trailer for a five-part series that will be published starting tomorrow and will deal with the various aspects of life extension.

Click on the tag "longevity series" to watch all episodes of the series.