Introduction to SARS-CoV-2

Since the end of 2019, humans have been dealing with the SARS-CoV-2 virus. First there was a local outbreak in China, then a rapid spread to the rest of the world. The fact that the virus emerged uncontrolled all over the world was initially due to the modern, almost natural mobility for work and holidays, and the large gatherings during parties, such as (Chinese) New Year and Carnival. After some delay, humanity’s backlash started around the world, as regionally phased as the original spread of infection.

In all communication about this pandemic, I notice how little explanation is given in language that is understood by everyone. Explanation in the sense of background information. I do hear projected doomsday scenarios, and what we should do against them, what consequences there are of whether or not we follow guidelines (including the legal framework in which everything must fit), and what the influence of our actions is on research statistics. I hear visions and opinions from specialists from their professional perspective. But I hear little background, and it seems as if everyone is expected to have the correct technical-scientific basic knowledge. But that’s not true. Most people follow the government because they don’t know any better. A large group is frustrated because of all limitations, others don’t believe in it, and still others don’t understand the sometimes very contradictory measures.

For those not so familiar with the world of chemistry and biology, a summary is provided below in simple terms. It provides background information and some explanation about the virus and the symptoms it causes. For the sake of convenience, I’ll stick to common parlance in this article, calling everything ” Corona “, although this isn’t scientifically correct. The context then shows whether it concerns the virus or whether the symptoms of the disease are meant.

There are many viruses, which are divided into groups based on specific characteristics. The SARS-CoV-2 virus belongs to the corona group, often characterized by a spherical appearance. The symptoms in the airways that can accompany an infection are summarized under the heading COVID-19. This is a set of symptoms that, if they jointly occur, are related to an infection with the SARS-CoV-2 virus. In addition to the normal flu and cold symptoms, this is mainly shortness of breath and low oxygen levels in the blood.

A virus is organic material, but that does not mean it is alive, like a bacterium, or other single and multicellular creatures (such as humans). A living organism has its own energy management, metabolism and a certain autonomy. If one of these 3 stops, that organism dies. A virus can be active or inactive (see explanation below). In the active phase it can react with substances from the environment, and in special cases reproductions of the original virus can arise.

Everything is made up of atoms of the periodic table of elements. These can in turn form molecules, crystal structures and connections, and with that ultimately the matter that we see around us and of which we are made up. Such elements are, for example, uranium, iron, copper and aluminum, but also carbon, hydrogen, nitrogen and oxygen. Depending on the circumstances, the form in which elements occur can vary greatly. Silicon, for example, occurs as loose sand, as gravel, and as glass and opal.

Inorganic chemistry is concerned with all these elements and their appearance, and how they can react with each other to form new substances. Consider, for example, metal alloys or water (molecules of 2 hydrogen atoms, bonded to one oxygen atom). Molecules usually have a limited size, which for larger shapes may clump together in crystal structures.

Organic chemistry is concerned with a special subfield, namely that matter which consists of large networks in which carbon, hydrogen, nitrogen and oxygen atoms occur, possibly (deliberately) “contaminated” with traces of other elements. These can be really gigantic chains compared to molecules. Depending on the sequence and structure of such “hydrocarbon chains”, you get substances with special properties, such as oil, plastics, rubber, aggressive glues and so on. An eye-catching feature of organic material is that it can burn, or rather: char (some carbon remains). Actually, it doesn’t take much energy to change organic matter, as we have all experienced.

Organic compounds and materials underlie everything that lives. If biology describes the structure of a cell with wall, plasma, nucleus and mitochondria, then the chemical composition of those building blocks is predominantly organic. The DNA, which determines the behavior of a cell, is such a special chain of organic material. But just because something has an organic composition does not mean that it is alive, just as the parts of a cell are not alive in themselves, but the combination thereof (in the right circumstances) is. A bacterium is an example of this.

A virus is clearly not a living cell: it is a piece of DNA-like material, wrapped in a protein coat. It is also very much smaller than a cell, so small that it is not visible under ordinary microscopes. Chemically, a virus is organic, but it is not an organism in a biological sense. Because it is not alive, it cannot die. It can be damaged, and like other materials decompose or change under the influence of external conditions. The shell can dissolve, or the DNA can crumble. It is inactive if it is not damaged, but cannot bind to organisms necessary for reproduction in the environment in which it resides. In a nutshell, an animal body is a good environment for a virus due to temperature, the absence of extreme (UV) radiation, and the presence of proteins and moisture. Everything else is more hostile (including, for example, soap and alcohol).

When a virus meets the right cell, the protein coat sticks to the cell wall and dissolves it a little. The virus DNA can then enter the cell and crawl, as it were, spoon-spoon against the right pieces of the much longer DNA chains, and soak them off. As a result, that host DNA breaks down, and the behavior of the cell itself changes. Instead of a useful, functional building block in the body, it suddenly becomes a foreign or even a hostile organism. The proliferation of virus DNA creates a kind of avalanche effect of cell changes, resulting in affected organs. The body’s defense mechanism responds to this by sending antibodies and white blood cells to it. Usually it is possible to get the infection underneath, but during that time someone feels very tired, limp and sick. When everything is over you have to build up strength again, replenish reserves and hope that the organs where the virus was active had not suffered too much from the attack.

In fact, the affected cells in your body are the pathogens, not the virus itself. The body does not react to the virus, but to the response of the affected cells. This is different from a bacterial infection. This also makes it difficult to find a medicine, because you do not know where the virus is nesting, and you want to spare that infected organ with the medication. Furthermore, the virus replication is not completely flawless: genetic mutations occur. You do not know in advance what the result will be. Hence, the emphasis of medical treatment is on antibodies and strengthening the immune system (immunity). The current Corona virus settles in the mucous membrane from the nose to deep in the lungs, which makes the fight even more complicated. Other flu viruses are only active in the nose or throat.

A virus needs a suitable (bio) carrier to move. An animal or human can easily take the virus elsewhere. A virus has a limited shelf life without a protective bio-carrier. Consider, for example, a drop of saliva on a door handle. Once that droplet evaporates, or is wiped away with cleaning products, the viruses in it are also destroyed.

In order to infect a healthy person, the virus must be transferred from the carrier to a vulnerable place (in the case of Corona, this is the mucous membrane of the respiratory tract). Many tiny droplets of body fluid are released into the air through the nose and mouth during breathing and talking. The more actively the lungs work, the stronger the emission, such as when singing, shouting, sighing, and so on. We carry a cloud of droplets around us, as it were, in which many viruses may also be present. Wind and the slipstream of physicalexercise make that cloud more extensive than we might expect. If a healthy person inhales any of that contaminated cloud, there is a good chance of contamination. Sooner or later, depending on size and weight, those droplets descend. That explains the need for keeping your distance, and actually not talking unnecessarily, and keeping your face averted where possible. Only that is socially very unfriendly. By the way, contamination does not always lead to infection. That is also the problem: you can carry the virus with you without having any symptoms of disease, and still spread it unnoticed. When you are infected, reproduction greatly increases the number of viruses in your body, and you are much more likely to infect others.

The same goes for shaking hands and hugging and touching each other: that is part of our social interaction. Unfortunately, we also use our hands to sneeze in, with or without a handkerchief (the alternative: sneezing and spitting in the open air is considered very unhygienic in many Western countries, except on the soccer fields 🙂 ). Or we unconsciously wipe our nose because of a ticklish nose hair. And rub our eyes when they feel a bit dry. With that we can move some moisture with virus inside. Therefore, it is advised to avoid contact, sneeze in the elbow, and use a tissue paper only once. And, especially if you are infected, regularly clean your belongings (such as clothes and telephone). Not all that useful in everyday life.

The explosive increase in the number of viruses is of course strongly related to the possible spread of infections. And just as a body is a good breeding ground, a high population density is an enormous stimulus for exponential growth in the number of cases of disease. Hot spots are therefore mainly located around the large cities. The more viruses that are active, the more variants are created. A new and more contagious variant will attack healthy and already healed people, thereby supplanting previous versions. From a macroscopic point of view, however, it is bad for a virus if all hosts were to die, or if everyone isolates themselves: then that variant vanishes. Ultimately, therefore, there will be a virus variant that can spread easily, but whose effects are no longer really life-threatening, much like what happened with other flu viruses.

It may be useful to clarify the following differences (in many communications they are used interchangeably, resulting in a lot of misunderstandings and differences of opinion):

  • Pollution: virus-containing material is present on a surface, for example your telephone or your hands.
    Remedy: Regular washing and cleaning.
  • Contamination: the virus is in your body, but is well controlled by, for example, antibodies.
    Remedy: healthy food, strict hygiene and keep a distance from others.
  • Infection: Tissues and organs are affected by the virus, weakened by it, and the virus is likely to multiply with DNA material from the affected cells.
    Remedy: vaccine to be developed, drugs and food that inhibit virus growth, drugs that support the affected organs, and patient quarantine and medical protective equipment for the environment.

The aforementioned hygienic protection measures actually always apply, also against other pathogenic viruses. Why is it suddenly so emphasized now? The main reason for this is the unfamiliarity with the corona virus. It is a variant that we do not know well enough, for which there is no vaccine yet, and that affects our body more strongly than other viruses (or perhaps we have become more accustomed to those over time). People with a weaker constitution (many elderly people or people who already have other diseases) are more susceptible due to the reduced resilience of their cells. This may be due to one-sided nutrition, lack of exercise, or just physical wear and tear, as a result of which the metabolism no longer works optimally. But that also applies to other viruses, one of the reasons why care centers are so alert to an influenza outbreak, for example.

Shortly after the outbreak, there was a large increase in hospital admissions. The direct cause of this is not so important (and unfortunately all too often the subject of interpretation, opinion formation and discussion). Hospitals are designed for the normal seasonal problems and the corresponding numbers of patients, in such a way that the care for non-flu-related cases can continue as usual. Alarm bells went off when hospitals became overcrowded with corona-contaminated patients. In order not to face ethical or moral choice problems, one had to try to contain the wave of infection. That was the reason for the former advice on social distance and hygiene.

Unfortunately, humans love to be herd animals. This means that they prefer to move in large groups, chatting and laughing with each other, and very often also changing groups (” from the shop to the café “). There are films made from a certain height about how streams of people move through streets and across squares at certain times of the day. When you see that, you immediately understand the problem: that is an ideal situation for a virus to spread. When the problems for healthcare threatened to become too great, mobility was the first to be restricted: stay at home, and only go somewhere when absolutely necessary. That worked quite well, but you can’t keep it up for long (sooner or later the herd breaks loose again). The destinations were then limited, so that there is less reason to go: restriction of leisure traffic and border crossings, closing of restaurants, cafes and other entertainment venues, which also prevents congregation in small spaces. And successively more and more separate measures were added, which often contradicted each other because (requested) exceptions were allowed, such as for children and at schools. Sometimes the remedy seems worse than the ailment (wearing a non-medical face mask for too long, just to raise awareness). All this brings confusion and misunderstanding. So actually we have to go back to basics: if everyone makes sure that he / she does not inhale a droplet from someone else, or emit it when someone is around, then it should be fine. Taking responsibility towards yourself and your fellow man, possibly making use of the many advice. And wait until we get used to this virus, just like the other viruses we are exposed to every year.

Also interesting...