Coronavirus left the immune response – Newspaper Kommersant No. 41 (7486) of 03/13/2023

The official coronavirus portal Stopcoronavirus.rf announced that it was suspending the calculation of data on herd immunity against COVID-19 and the number of those vaccinated. The decision was made, among other things, due to the fact that antibodies to COVID-19 were found in many people who were not vaccinated and did not have clinical manifestations of the disease. Rospotrebnadzor explained to Kommersant that previously statistics were used mainly for planning restrictive measures. Under the current conditions, this practice is no longer necessary.

“In the context of the dynamic emergence of new variants of SARS-CoV-2, changes in the clinical picture and a decrease in the severity of the course of the disease,” the Stopcoronavirus.rf portal suspends the calculation of data on herd immunity against a new coronavirus infection and the number of those vaccinated. Information on the number of people who have been vaccinated will be periodically published by the Russian Ministry of Health along with data on influenza vaccination.

Thus, only statistics on daily detected cases, as well as the number of hospitalizations and the number of people who have recovered over the past 24 hours, remain on the official resource.

The indicator of the level of herd immunity against COVID-19 was initially calculated in accordance with the epidemiological and mathematical model, which takes into account the number of people who recovered from the disease and were vaccinated over a certain period of time. This calculation method was relevant when there was an insufficient number of people who were ill and vaccinated, and the task was to achieve herd immunity from COVID-19 as quickly as possible. However, the accumulated data of scientific research allow us to consider the use of such an approach for calculating herd immunity as “irrelevant”. According to the information resource, over the entire period of the pandemic, 73 million Russians have been fully vaccinated against coronavirus at least once. However, the results of screening studies for antibodies to COVID-19 suggest that they were found in many of those who were not vaccinated and did not have clinical manifestations of COVID-19.

Deputy Director of the Central Research Institute of Epidemiology of Rospotrebnadzor, Academician of the Russian Academy of Sciences Alexander Gorelov notes that previously knowledge about herd immunity was used mainly for planning restrictive measures. Under the current conditions, the maintenance of operational statistics in this form is not required, since a certain level of herd immunity has been achieved, supported by several factors.

“Among the significant factors, we should mention the very scale of the spread of the coronavirus, past rises in the incidence, high circulation and infectiousness of the “omicron”, as well as mass vaccination. In addition, we see that the disease itself is gradually acquiring the features of a seasonal respiratory pathology,” says Mr. Gorelov.

The severity of the course of the coronavirus has indeed been steadily decreasing. The strain provoking the most complex clinical picture was “delta”. Through his fault, in the summer of 2021, a third wave of coronavirus occurred in Russia. The federal operational headquarters did not publish data on the number of hospitalized at that time, but the situation can be assessed according to statistics from Moscow, which traditionally has the highest rates in the country. So, on June 15, 2021, 6805 new cases of infection were detected in the capital, and 1705 patients were hospitalized – 25%. Delta has been replaced by a more contagious but less aggressive strain, Omicron. It caused several waves of infections, when the number of daily detected cases reached six figures. However, the number of hospitalizations has decreased. For example, on February 3, 2022, 26,904 new cases of COVID were detected in Moscow, while 1,622 people were hospitalized – 6%. The current surge in incidence is associated with numerous sub-variants of the “omicron”, each of which, judging by official data, is becoming more contagious, but softer than its predecessor.

Denis Gusev, chief physician of the Botkin City Hospital in Moscow, said that the portrait of a patient with coronavirus has also changed. According to him, before the hospital mostly got people over the age of 65 years. Now hospitalization is more often required for citizens over 80 years old. At the same time, coronavirus is far from a priority problem for these patients. As a rule, they need complex treatment. COVID-19 itself, according to the doctor, is now much easier. Most often, it is characterized by symptoms of acute respiratory infections and lesions of the upper respiratory tract without the development of pneumonia.

The decision of the official portal not to publish some data suggests that there is no longer an acute situation and outbreaks that would overload the health care system, says Sergey Kharitonov, a molecular biologist and researcher at Moscow State University.

“Obviously, clear approaches have been developed on how to work with patients, vaccines, treatment protocols, and therefore these data have become less relevant,” says Mr. Kharitonov. However, he does not rule out “other – perhaps administrative – reasons” for stopping the publication of some of the data. Elizaveta Temnik, an infectious disease specialist at the Doctis telemedicine service, notes that the target vaccination rates have not been achieved – moreover, they continue to fall. Note that the last time herd immunity was reported was at the end of the summer of 2022, when it was 7.4%.

“Nevertheless, the immune layer is already significant, including the so-called hybrid immunity acquired by the population after illness and as a result of vaccination. This gives more chances, firstly, not to pass it on to another, and secondly, it is easier to transfer infection with a new version of the virus, ”explains Elizaveta Temnik. However, she notes, experts also observe the opposite phenomenon – immune imprinting or antigenic imprinting: people who have been ill with old versions of the coronavirus (before the “omicron”) or have been vaccinated against them have a high risk of getting sick with new ones. The problem, according to the infectious disease specialist, arises when the immune system collides with a new version of the virus, similar to the previous one (for example, when infected with “omicron”). Instead of creating new memory B cells, the immune system triggers a response of existing B cells. As a result, antibodies are directed against those epitopes (parts of proteins) of the virus that are identical in the new and old variants (for example, in “alpha” and “omicron”). And new antibodies that more effectively neutralize the new variant are produced poorly. “Therefore, people should still treat the infection with caution,” warns Yelizaveta Temnik.

Sergey Kharitonov believes that it would be useful to follow the reports of changes in the symptoms of coronaviurs: “Now many different variants are circulating in the population. They are changing some details related to distribution, they are a little better – but not fundamentally better – starting to move away from vaccines. But the radically new properties are what could change the course of the pandemic.” However, he admits, there are no such data yet, and everywhere in the world the situation is under control.

Natalya Kostarnova