Don't rush to bury vaccines
Experts: There is no reason to give up on the creation of a vaccine
Irina Nevinnaya, Rossiyskaya Gazeta
Several European publications reported disturbing news at once: tests of patients who had been ill with COVID-19 a few months ago showed that the number of antibodies in their blood was rapidly decreasing. As a result, the authors of the publications suggested that the vaccine against the new coronavirus, which is being worked on in many countries, including Russia, may be ineffective and will not protect against re-infection.
This version is given in the German newspaper die Welt with reference to research conducted at the Munich clinic Schwabing (München Klinik Schwabing). Scientists from King's College London, who tested more than 90 patients and medical workers of the National Health Service Foundation of Great Britain (NHS) who suffered COVID-19, also reported that the immune response to an infection that has entered the body is rapidly disappearing.
British scientists have found that 60 percent of infected people had a maximum level of antibody production three weeks after the first symptoms appeared. But three months later, only 17 percent of those observed retained strong immunity to the coronavirus, The Guardian and The Daily Mail reported. So doubts were expressed not only about the effectiveness of the future vaccine, but also that the epidemic will end naturally when 60-70 percent of the population is ill. After all, if those who have been ill become vulnerable to the virus again in a few months, it will not be possible to achieve population immunity, repeated infections will begin.
Meanwhile, yesterday it became known that the first Russian vaccine against coronavirus infection may be registered as early as early August. In Russia, immunity studies are also being conducted in people who have suffered COVID-19. Among others, such a search is carried out by a group of specialists of the Genetico Center together with other scientific organizations. "RG" asked the director of the center Artur Isaev to tell about the interim results of the research and comment on the data of foreign scientists.
– I would be very careful about such publications and not make hasty conclusions – because research is ongoing. Let's remember: even at the beginning of the epidemic, it was suggested that immunity to a new infection would be unstable, if at all. And such versions were based on the fact that long–term immunity is not developed to other similar viruses – coronaviruses. But now, six months later, more data has appeared and it is possible to analyze them.
Yes, the constant high level of antibodies and the intensity of immunity to this virus is unlikely to be, since the features of the virus proteins prevent this. This is a common thing – we know that there are infections that it is enough to get over once and get protection for the rest of your life. And such a strong immunity is not formed to other infections. The fact that the number of antibodies in patients decreases over time was expected.
On the other hand, even when there are no antibodies in the blood of those who have been ill, antibody immunity is quickly activated. Memory B cells begin to produce the necessary antibodies as soon as the virus enters the body. But for further protection in case of repeated encounter with the pathogen, another type of immunity is important – cellular immunity, T-lymphocytes. They have a special "memory" and upon re–infection, they recognize the virus and the cells infected with it and destroy them, elimination occurs - the "purification" of the body from the virus.
There is evidence that cellular and antibody immunity is formed not only in response to SARS-CoV-2, but also to other similar coronaviruses – and if a person has met them before, then when infected with a new coronavirus, the body copes with the disease more easily. This is one of the possible explanations why the majority of infected people carry the disease in a mild form.
Our research began in April. What have we already seen? The level of antibodies in patients is different. Moreover, there is a pattern: a higher level of antibodies in people who have been ill with severe symptoms. Those who have suffered the disease easily or asymptomatically often have low titers. But a decrease in the number of antibodies in the blood does not mean a lack of immunity, it's too early to talk about it.
We are also studying cellular immunity, and we can already say that it is produced in the absolute majority of those who have been ill. But it is also difficult to say how long the antibody and cellular immunity will protect against the invasion of the coronavirus in the future. It is encouraging that although studies are conducted by many researchers in many countries, there is not a single publication that reliably confirms cases of re-infection. This, as you know, is very important. Therefore, we cannot say that it is impossible to create an effective vaccine.
At the same time, a very important area of research is the study of antibody–dependent amplification of infection. The very "malfunction" in the immune system, when in response to the virus, such a paradoxical interaction with antibodies and massive damage to the cells of the immune system begins, that a strong inflammatory reaction occurs – the very cytokine storm about which so much is said. It is extremely important to understand what role this process plays in severe cases of COVID-19. Not only to understand the nature of the complication and learn how to avoid it, but also to create a safe vaccine. We are also working on this now.
Portal "Eternal youth" http://vechnayamolodost.ru