In the cold season, we often encounter a variety of ARPs, so we are not particularly surprised. And now many do not understand why such serious restrictions are needed (cancellation of various mass events, self-isolation, quarantine, introduction of the emergency regime in some countries, etc.) with the seemingly ordinary ARI in the form of COVID-19. Indeed, COVID-19 is an ORD (or rather ARVI), but that's not quite usual.

First, different viruses that cause symptoms of SARS prefer different parts of the respiratory tract (we read about it here). If the most common and most "light" viruses usually do not pass beyond the nasal mucosa or larynx, the SARS-CoV-2 virus, which causes COVID-19 disease, prefers pulmonary alveoli, causing viral pneumonia. Viral pneumonia does not have antibiotics, they do not currently have drugs – they can cope only the body of a particular person, having developed the appropriate antibodies and getting rid of the virus. But not every organism by virtue of its condition can survive this struggle without consequences. Here we have such a concept as "risk group" (most often severe course is observed in people over 65 years of age, as well as in people with somatic diseases (in particular, heart, lung, diabetes, cancer, hypertension), regardless of age).

There are not many viruses that prefer to settle in the lower respiratory tract. As a rule, we encounter most of them as a child and develop a persistent immunity to them. In this regard, most of childhood pneumonia and bronchitis is viral, but in adults – bacterial. Accordingly, for an adult, viral pneumonia is an exception rather than a rule.

Secondly, SARS-CoV-2 is a new virus for humans. Accordingly, we do not have collective immunity to it. This means that when you meet it, each organism starts to produce antibodies. When at least 60% of the population encounters this strain and develop antibodies to it, then the probability of infection of the remaining 40% will be significantly reduced. Accordingly, the incidence of diseases will decrease. In the meantime, there is no collective immunity – we are witnessing just the situation when all who meet with the new virus (someone just asymptomatic produces antibodies, but about it a little below).

Third, COVID-19 is highly contagious, i.e., the speed of distribution. Now they say that it is more contagious than the flu about 3 times.

Fourthly, judging by what is happening, SARS-CoV-2 feels good, including in the warm season, as countries with hot climates also suffer from it. Accordingly, it is far from the fact that with the arrival of heat the situation will change greatly (while standard viruses that cause SARS, as a rule, are more active in the cold season).

Fifth, the virus eventually adapts to the person, mutates. Viruses tend to gradually weaken because their goal is not to destroy the carrier, but to multiply. Accordingly, it is possible that after some time the symptoms of COVID-19 patients will be less pronounced.

According to Italian statistics, at the moment about 60% of people suffer COVID-19 almost asymptomatic or with "smeared" symptoms (light degree). But the remaining 40% may require medical care. According to some data, 50% are asymptomatic or mild, and for others – up to 80%. However, about 5-15% of people who carry COVID-19 are very hard (up to the fatality) remain. This is quite a big indicator. According to WHO statistics, about one in five people need medical attention. At the same time, one in six cases is accompanied by severe symptoms with the development of respiratory failure (mostly in patients at risk).

There is no clear answer as to why this is happening at the moment. Different countries are different. This is due to the population density per square meter, and the customs of a particular country (e.g., whether several generations live together or separately, whether it is customary to gather large companies, close communication or adherence to distance, etc.), with the level of social policy and medicine (as many representatives from the risk group, access to medical care, frequency of antibiotic use, etc.). In addition, there is an assumption that the presence of a patient vaccinated BCG reduces the likelihood of a severe course of the disease. It is also suggested that in the northern regions, where there are frequent SARS, most people have already encountered other strains of coronaviruses, so it is easier for them to produce antibodies, as the similarity of strains is about 70%.

In general, there are mass assumptions. They will be confirmed or disproved – time will tell. And we move on to the issue of COVID-19 prevention and the need for quarantine.

Since the pathways of coronavirus transmission are the same as those of other viruses that cause SARS (the main one is airborne, contact, fecal-oral and airborne (through ventilation) – prevention measures are not particularly different from other SARS. This is frequent hand washing, use, if necessary, antiseptics and gloves, lack of contact of dirty hands with mucous, restriction of contact with other people (if possible to avoid at all or at least to keep at all at a safe distance (at least 1 meter)), wearing a mask carriers of the virus, frequent wet cleaning and airing of premises, leaving street clothes at the entrance to the room, thoroughly washing food, etc.

The quarantine allows to reduce the number of contacts between people, and therefore to implement the main point of prevention of the disease. Of course, if a vaccine is not developed before the end of the quarantine, which will allow all the population that does not suffer, the disease will continue. However, quarantine allows you not to get sick all at once, and stretches the process in time. This is necessary in order to unload the health system and allow it to cope with the number of serious patients ining. The problem is not only that there may not be enough medical personnel, hospital beds, protective equipment, medicines (yes, COVID-19 is not yet a drug with proven effectiveness, but often requires measures to reduce symptoms, treatment of related diseases and complications from the virus) and the necessary equipment for the treatment of PATIENTS COVID-19 (although this is certainly a problem), but also that other diseases will not be reversed by the disease). and all forces will be thrown to fight the pandemic. Accordingly, without medical care can be a huge number of people. In addition, the doctors themselves gradually begin to get sick and fail. And doctors, according to the experience of European countries, are ill, because fatigue, concentration of the virus, etc. are affected.

Thus, it is possible to cope with a pandemic with a minimum of losses either through the gradual development of collective immunity ("smearing" the number of diseases over time, so as not to overload the health system), or by vaccinating the population. It is unrealistic to develop a vaccine so quickly and to vaccinate it all. So many countries have gone down the path of quarantine. Is it possible to do without universal quarantine? Most likely, yes. But to do this, everyone must clearly know and observe preventive measures. Can the state vouch for every person? Probably not. Therefore, it is easier, alas, to prohibit leaving the house at all.

So, despite the fact that COVID-19 is just ARVI, there are nuances. They are connected mainly with its novelty for humanity, the speed of spread, the severity of the flow in people at risk. They will probably not get sick, but if you are not at risk, the probability of suffering the disease with mild symptoms or in general asymptomatic – about 80%. Our main goal now is to comply with preventive measures as much as possible to prevent large numbers of people from being infected at the same time and not to overload the health system, which should significantly reduce the number of victims of the pandemic.