Today, the internet is spewing thousands of fakes about the coronavirus. For example, that immunity to COVID-19 is very fragile. Say, a few months – and there is no trace of immunoglobulins G, which the body has developed in response to infection or vaccination. What does this mean? Will we start hurting again? They also say that mask mode no longer works. Better to just get sick – and not think about the virus. There are many questions, fears and conjectures. The director of the Irkutsk Research Anti-Plague Institute of Siberia and the Far East, Doctor of Medical Sciences, Professor Sergei Balakhonov helped Rossiyskaya Gazeta understand all this.
Covid is not so contagious
Sergey Vladimirovich, our readers often share information that one or two people in the family got coronavirus, and all the other household members did not get infected. Why does this happen?
Sergey Balakhonov: Such cases are not uncommon. Several factors come into play, I believe. Firstly, SARS-CoV-2 is not as contagious as, for example, the influenza virus. Therefore, it is enough to isolate the sick person in a separate room, regularly ventilate the room, rinse common areas with disinfectants and use UV recirculators.
Since the family is aware of the disease, it takes safety measures, including the use of drug prevention regimens.
Secondly, people have completely different sensitivity to the virus, which is determined by their individual immune status. Congenital nonspecific immunity also plays a role. There are factors that prevent the penetration of the pathogen into the body. For example, the production on the mucous membranes of an increased content of lysozyme and some other enzymes. These nonspecific factors of innate immunity work against all respiratory pathogens and kill them before they enter the cells of the body.
And, thirdly, it is quite possible that coronaviruses have already visited the body of relatives-contactees, and now memory cells resist the infection.
Does it mean that these people will not be infected with SARS-CoV-2 from other patients?
Sergey Balakhonov: Not at all. And I don’t think it’s worth checking this. There is always a risk of a breakthrough in immunity, no matter how strong it is. Again, in the same apartment with a sick person, you observe all safety measures, and this is reasonable. In public places, in particular in transport, social distancing and other sanitary rules are not followed by everyone.
The virus stays in memory
You talked about memory cells. Is this cellular immunity? Has your institute already started studying it?
Sergey Balakhonov: Yes, within the framework of the second stage of research on the formation of population immunity of the population of the region, we have carried out a certain group of studies to study cellular immunity.
It should be noted here that the level of formation of cells producing antibodies is very different and depends, rather, on the individual characteristics of the organism of individual volunteers, rather than on the quantitative indicator of specific immunoglobulin G and the severity of the disease. But the fact that these cells have been found is a fact. We believe that the third stage of research, which will take place in December, will provide us with more information, including for comparative analysis.
And how long do memory cells “recognize” the pathogen?
Sergey Balakhonov: According to general scientific knowledge about the formation of immunity to viral diseases transmitted by airborne droplets, it takes a long time – up to two years. As for SARS-CoV-2, research is ongoing, because we do not yet have a long period of time since the onset of the disease. However, information about the closest “relatives” of the current coronavirus is encouraging.
“Relatives” are other coronaviruses?
Sergey Balakhonov: Yes, it is SARS-CoV-1, known as the causative agent of SARS-SARS, and MERS-CoV, Middle East respiratory syndrome. These viruses caused epidemic complications in certain areas in 2002-2003 and 2012-2018. They are dangerous in that among those infected with them, a high level of deaths was recorded.
Since these coronaviruses have almost 80 percent genetic identity with SARS-CoV-2, they have generated a lot of scientific interest in maintaining immunity to viruses. Research findings from the US and Singapore have recently been published in scientific medical journals. And it turned out this: memory cells for these pathogens were found in the blood of people who had undergone diseases caused by these viruses. But it took from 5 to 12 years!
And that’s not all – there is evidence of the possible presence of cross-immunity. That is, cellular immunity to other coronavirus infections is also effective against COVID-19.
Only once in a life there is a meeting
How do you explain the fact that in Russia not a single case of re-infection with COVID-19 has been officially registered? Whereas, according to the stories of “relatives of mutual acquaintances,” such cases are quite common.
Sergey Balakhonov: Worldwide, with millions of cases, several dozen such cases are officially registered. And each of them has its own, specific, reasons that led to re-infection.
By the way, at the beginning of the epidemic, in March-April, panic moods on this basis were much more active. People came to our institute with statements that they were sick with “something just as terrible” back in November-December last year, and in May they became infected again. Retrospective analyzes did not reveal any changes in their immune status.
That is, the likelihood of re-infection is unlikely?
Sergey Balakhonov: Yes. Because both humoral (protection by antibodies) and cellular immunities work. And mutations in the genome of this virus, fortunately, are not as significant and significant as it happens with the influenza virus.
At least at the second stage of studies on the formation of population immunity among volunteers, there were no facts of recurrent COVID-19 disease from June to November in our region.
And if we, journalists, find a person who has been infected again? And this fact will be confirmed by the results of PCR and ELISA analyzes. Will you explore?
Sergey Balakhonov: You just need to find a sensation! Of course we will. In principle, anything can happen. What if this conditional person had been ill at home, and then flew to the USA or Australia and there he met with a coronavirus of a different phylogenetic line (generic – Ed.)?
So there are still strains of the coronavirus that are significantly different from each other?
Sergey Balakhonov: Yes, the differences in the course of evolutionary divergence have been recorded. The original (Wuhan) SARS-CoV-2 virus, when spreading around the planet, was divided into several subtypes: European, American, Australian, etc.
And in Russia what?
Sergey Balakhonov: On the territory of Russia, the spread of the European variant of the virus and its divergent (separating – Ed.) Derivatives continues. Wuhan, by the way, practically did not reach us, thanks to timely closed borders and rapid localization of outbreaks in China. But the Chinese themselves sounded the alarm just about the delivery of the European variety of coronavirus to them.
So you can still get infected again?
Sergey Balakhonov: Yes, isolated cases of re-infection have indeed been described. But this is rather an exception, against the background of immunodeficiency and oncological complications. Therefore, there is no reason to panic.
When this is all over
More than 30 thousand people have been infected with coronavirus in the Irkutsk region. All over Russia – more than two million. When will it all end?
Sergey Balakhonov: Stabilization and relaxation of the tension of the epidemic process can be expected when the herd immunity rate reaches 65-70 percent. The spread of the virus stops. The pathogen loses its ability to circulate in the population.
Immunity consists of post-infectious and vaccine. Now in the Irkutsk region the level of post-infectious immunity is close to 14 percent. Let’s carry out the third stage – we will get a new figure. Then it will become clear how many people should receive the vaccine.
We must endure and observe social and sanitary standards so as not to get infected. And wait for the vaccine trials to complete.
Masks, they say, no longer save the situation …
Sergey Balakhonov: Wearing masks, maintaining social distance and disinfecting rooms and hands – save. There is such a concept – “mask coefficient”. If more than 80 percent of the population uses these personal protective equipment, morbidity and mortality are significantly reduced.
If European countries achieved 80 percent wearing masks, they could save 33 thousand lives – this is the result of modeling the situation by one of the authoritative scientific centers. Again, the experience of China and other Asian states shows that masks, quarantines and restrictions on social activity work.
In China, thanks to strict restrictive measures, with full mutual understanding between the authorities and the population, it was possible to stop the pandemic. Since the beginning of the year, they have registered just over 86 thousand cases of infection. The USA covers this value in less than a day, Russia – in a week. Is this not an argument in favor of medical masks?
What do you think about such moods: why pull, hide from infection? Maybe, to get infected on purpose, get sick, and live in peace …
Sergey Balakhonov: This is, of course, a dubious “lottery”. After all, it is completely incomprehensible how the disease will proceed and what complications can emerge after it? And one more question is ethical. If you don’t feel sorry for your health and life, then you should think about how many people you will infect, and how many of them will die … I am sure that it is more civilized, more humane to accept restrictions and wait for mass vaccination.
Changing of the Guard
Sergey Vladimirovich, did not the antibodies disappear from those people who had been ill with COVID-19 in the Irkutsk region in the first wave, from March to May?
Sergey Balakhonov: According to the results of the second stage of studies on the formation of population immunity, which has been carried out in 26 regions of Russia since June, the Irkutsk region entered the top 15 regions in which the immune layer has increased by one and a half to two times. If at the end of the first stage it was 5.3 percent, now it is almost 13.
Note that initially the number of antibodies – primarily specific virus-neutralizing immunoglobulins G – varied in different subjects from minimal to very high.
The dependence of antibody formation on the severity of the disease was determined. That is, the stronger the virus attack was, the more antibodies were produced. After 3.5-4 months, the level of immunoglobulins of this class really decreased significantly in about 15 percent of those who had recovered.
Decreased but not disappeared?
Sergey Balakhonov: No. These antibodies are still detected in more sensitive quantitative assays. And even among volunteers who survived the disease almost six months ago.
Is there a chance that the antibodies will disappear and the person can get sick again?
Sergey Balakhonov: Immunity is a complex and balanced defense system of the body and it consists not only of immunoglobulins. A decrease over time in the indicators of humoral immunity (antibodies belong precisely to this part of the protective reaction) is a normal phenomenon. There is nothing catastrophic about this. And the rumor-fueled panic is completely unfounded. Because further the body will be protected by other constituent elements of immunity and, above all, cellular ones.
Why is the amount of antibodies-immunoglobulins reduced?
Sergey Balakhonov: As unnecessary. The person was cured, the pathogen left the body and there is simply no one to defend against at this moment. The number of antibodies is reduced, but the “image” of the virus is preserved in the “memory” cells – these are, in particular, individual subpopulations of B-lymphocytes. And in the event of a repeated attack, memory cells trigger a rapid immune response, again providing the production of immunoglobulins.
All materials of the plot “COVID-19. We can handle it!” read here.
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