Re-infection is an individual immune response, which can be considered an exception to the rule, ”Pavel Volchkov, head of the MIPT genomic engineering laboratory, told Izvestia. According to him, in the overwhelming majority of cases, the human body’s defense system reacts to coronavirus in a predictable manner, so vaccination is undoubtedly needed. The virologist considers the information of scientists that recovered people can excrete a pathogen for a very long time, up to three months, quite possible, but in any case he does not see the point in a new self-isolation.
– The head of Rospotrebnadzor Anna Popova said that a person who has recovered from COVID-19, according to the observations of Russian scientists, can excrete the virus for 48 days, and according to foreign data, up to three months. We found where this information came from, it is posted on website American Department of Health (CDC). Can someone who gets a viral infection be contagious for 90 days?
– American scientists are very careful to say that there is such a possibility. Unfortunately, I cannot answer exactly, I would like to see scientific articles about both 48 days and 90 days. But you can fantasize that in some cases, the immune system decides not to kill SARS-CoV-2 completely, since it is more expensive for it than taking the virus into a chronic form. Then one can imagine that the patient can excrete it for so long.
Photo: Izvestia / Pavel Bednyakov
– The CDC website says: the researchers did not find evidence that clinically recovered people with the preservation of viral RNA transmitted SARS-CoV-2 to other people. So a person only secretes a virus for 90 days or is he dangerous to others all this time?
– To answer this question, again you need to look at the detailed description of the study. It is not on the CDC website. But based on the logic of the existence of other viruses in chronic forms, we can say that it happens in different ways. I would like to see exactly how many viral particles the researchers found in patients with a long-lived infection. And then it will already be possible to draw a conclusion about the viral load, which is either dangerous to others or not.
– There is more and more talk around about re-infections. Many write on their pages that after the transferred COVID-19 they fell ill again. So immunity is not working?
– Most often, the described cases represent the continuation of the first infection, which remained untreated. If immunity did not work, we would see filled hospitals around, as it was in May. But we, on the contrary, are witnessing a reverse re-profiling of medical facilities and a long plateau of new infections. In addition, it is hardly worth discussing someone’s post on social media. And there are few scientific articles on re-infection.
The work of the department for patients infected with coronavirus in the City Clinical Hospital No. 52 in Moscow
Photo: Izvestia / Zurab Javakhadze
– But still there is. For example, an article describing a case of re-infection of a Hong Kong patient who was first infected with one strain of coronavirus, and four months later “caught up” with another.
– Yes, this is probably the most well-documented case of a secondary infection. This article does describe two different strains of coronavirus that were isolated from this patient. But for the immune system, they are still not different enough so that it could miss a secondary infection.
– But she missed it. So what’s up?
– Either this is some kind of error at the testing stage, or an individual reaction of the immunity of the Hong Kong patient. That is, it is his immune system that is not perfect enough to remember the coronavirus the first time. He may be immunocompromised, or he was on immunosuppressants at the first treatment. And he coped with the first infection, but the memory cells (cells that remember the pathogen so that when they encounter an infection next time they start producing antibodies – Izvestia) did not remember the pathogen. It would be nice, of course, to see the history of his illness.
– So re-infection is an exception to the rule?
– Why are you so sure of this?
– I proceed from the structure of the coronavirus itself and its capabilities. SARS-CoV-2 does not mutate enough to infect a person again. By all appearances, we are dealing with special local cases.
Photo: Izvestia / Dmitry Korotaev
“But the flu virus mutates. And you can get infected with another strain of it in four months.
– The flu virus is completely different. It has eight segments and SARS-CoV-2 has one. He cannot change so quickly. And influenza can exchange these segments during coinfection (infection of one cell with different types of viruses – Izvestia). As a result, we see two different strains that are genetically much further apart from each other than the two strains of coronavirus described in the article about the Hong Kong patient.
– In addition to the Hong Kong patient, there was also a Nevada one and a scientific article attached to it. And if the first recovered easily, the Nevada patient’s disease after re-infection was more severe. Is this also an exception?
– Sure. Imagine, to date, according to official statistics alone, about 30 million people have become infected in the world. And we are talking about only two confirmed cases of re-infection …
Photo: TASS / Zuma
– Information about recurrent diseases is supported by scientists’ statements that those who have had COVID-19 quickly lose or do not acquire antibodies at all and therefore may become infected again. Recently, an article by scientists from Sechenov University was published, which they wrote in collaboration with Austrian researchers. After conducting experiments on the basis of the Vienna Medical University, they found that antibodies are produced only in 60% of those who have recovered. It turns out that 40% can get infected again?
– I read this article. There the experiment is set up with limitations. To conduct it, scientists took not the coronavirus itself, but only part of it (RDB domain). And they saw that 60% of antibodies reacted to this part of the virus. But the pathogen itself has other parts as well. And, possibly, other antibodies will react to them, which are quite diverse in the human body.
– What conclusion can be drawn after reading this article?
– Conclusion that immunity works, and it works very well. That as many as 60% of patients react to only one part of the virus. To be honest, I thought less. Immunity and its reactions are very individual, everyone has it in their own way.
Photo: Izvestia / Dmitry Korotaev
– In the same article it is said that some antibodies “play on the side of the rival,” that is, they even help the virus to penetrate into a human cell. It’s true?
– Scientists Sechenovka clearly demonstrated in this experiment the well-known effect of antibody-dependent intensification of infection. Everyone who works with drugs and vaccines against SARS-CoV-2 knows about it. But again, they saw this effect on one part of the pathogen. In an amicable way, this experiment should have been carried out on the whole coronavirus, it is just that you can work with it only in laboratories of the third or fourth level (laboratories of the penultimate and last BSL (Biosafety level laboratory) level on the pathogen hazard scale. – Izvestia), for this many scientists prefer to experiment with parts.
– What would they see if they took the whole virus?
– That there is a struggle: some antibodies neutralize the pathogen, others, perhaps, enhance its penetration, but it is completely unclear who would take it.
Photo: RIA Novosti / Kirill Braga
– That is, such results do not negate the usefulness of vaccination?
– Not canceled at all.
– Now we see that in some countries – France, Spain, Czech Republic, Israel – the incidence has started to rise again. Why is this happening?
– I really don’t understand very well why. It turns out that these countries self-isolated well in the first wave. But Germany does not have such a two-humped schedule. Israel, which has just closed its borders again, generally adheres, from my point of view, to a strange strategy.
– What is its weirdness?
– They rush from side to side. If we imagine the global picture of the reaction of countries to the pandemic, then there are two extremes. Let’s call one “the Chinese concept” – it is good to self-isolate and suppress the outbreak with almost military methods, but then you will have to keep the borders shut. And at the other extreme, there is the “Swedish concept”, which means almost everything is allowed, business structures and educational institutions are closed to a minimum. So Israel is torn between these two concepts. First, they ban everything, following the Chinese strategy, and then they open the borders, following Sweden. This logic is incomprehensible to me.
Machane Yehuda Market in Jerusalem
Photo: TASS / EPA
– In Sweden, now, according to scientific articles, antibodies are at 17% in the population. In Russia, according to “Invitro”, 16.9%. So what happens: they didn’t close anything, we – on the contrary, and the antibodies are at the same level?
– The fact is that the level of antibodies in people who have recovered falls over time. And there is no point in comparing countries three to four months after the peak. Let’s say that everyone in Sweden had been ill, but after four months the level of antibodies in many of those who had been ill fell, and only those who had recently had been ill remained. But the bulk of the population still has immunity to infection, that is, the cells will remember SARS-CoV-2 when they meet it again. And it turns out that the same buffer immunity was formed, which the Swedes were going to achieve from the very beginning.
– Once you said that there would be no second wave in Russia. So far it does not exist, but in European countries an increase in the incidence is recorded. So, maybe we need to be ready for the second wave?
– In Russia, we do not observe either repeated infections or a second wave. We see a slight rise in the incidence, which can be called small fluctuations in the number of infected. But the line, as it was almost straight, remains so. Therefore, we definitely do not have a second wave. Small fluctuations can be explained by understandable things: people return from vacations, students come to their places of study, there is a slight mixing. But 142 million live in Russia, and we know for sure that the stratum of those who have recovered is already large. Especially in big cities. Therefore, there should not be a second wave. The regions that self-insulated well in March – April – May may “burn” a little.
Moscow during the regime of self-isolation
Photo: Izvestia / Pavel Bednyakov
– Russian business structures and educational institutions, just in case, prepared to close again for self-isolation. Do you think they will put us home a second time?
– I don’t see any sense in this. Currently, there is definitely no flow of covid patients in hospitals, while testing remains at a very high level. But they are already testing everyone. This happens because different organizations require a certificate, people themselves want to understand whether they have had COVID-19 or not. That is toThe number of seriously ill patients in relation to the number of those tested is already quite different than in May. Among the confirmed positive PCR tests, there are also more and more mild and asymptomatic forms. So why close when people can acquire immunity for free?
– The meaning of the first self-isolation was to have time to prepare medical institutions for the flow of patients, so that everyone could be helped. Can’t this situation be right now?
– I think no. But in any case, if hospitals and hospitals suddenly start to fill up, the authorities will have a chance to understand this and introduce self-isolation. In the meantime, let the buffer immunity layer increase.