Why there are no antibodies to coronavirus after illness

2024 Author: James Gerald | [email protected]. Last modified: 2023-12-17 14:00

The first reports that antibodies to a dangerous pathogen may not be in the blood of a person who had been ill appeared in the middle of last year. Within a short time, scientists have found two possible explanations for this phenomenon. The first explanation why there are no antibodies to coronavirus after an illness is the severity of the course. The second is cellular immunity, which also protects a person, causing the production of antibodies only after a repeated infection.

Probable guesses

Virologists can draw final conclusions only after the end of the pandemic and summarizing all the data obtained from scientific research, statistics and experience in treating the disease. The widespread prevalence of COVID-19 does not mean that all aspects are fully understood. Now doctors and scientists are busy looking for ways to stop the spread, methods of treatment. There are hypotheses that require large-scale studies to confirm, for example, whether older people actually produce fewer antibodies, or why there are no antibodies to coronavirus after illness in 5% of those vaccinated.

V. Zverev, the head of the Department of Immunology at Sechenov University, believes that there may be several explanations for this phenomenon:

• the reason for non-detection of antibodies after immunization may be poor-quality diagnostics, the use of an insufficiently sensitive testing system;
• short time elapsed after vaccination; in some people, the immune system works more slowly and does not have time to develop a level that can be detected;
• The drop in antibody concentration can be explained by the onset of cellular immunity (the second protective level), which triggers the production of antibodies when a new collision occurs.

E. Pechkovsky, a member of the Presidium of the FLM RF, is sure that the first assumption has the right to exist, since several testing systems have been developed and each of them may have its own parameters. Therefore, it makes no sense to compare data from different laboratories. Cellular immunity is the most likely explanation for why there are no antibodies to coronavirus after an illness: the presence is explained by contact or the presence of an antigen. A person who has recovered has an instruction that is fixed in memory cells, but the production of new antibodies starts only when there is an urgent need.

The molecular biologist is sure that the reasons for the discrepancies in the level may be even at a certain time of the day at which the analysis was carried out. Another reason is the lack of a direct test: all the methods used are indirect, approximately determining whether there are many or few antibodies in human blood.

Interesting! What antibodies should be for coronavirus after illness

Scientific explanation

It was received by foreign researchers, but was initially rejected because they considered that there was very little practical material (only 7 families were surveyed). The laboratory of the National Medical Research Center of Hematology is closely engaged in the study of people who have come into contact with patients with COVID-19, but did not become infected, and they did not have antibodies to the disease. In the laboratory of transplant immunology, analyzes of these people were examined. As in the first case, there are still no statistical generalizations, but T-lymphocytes were detected in a significant number of objects.

This element of immunity is a very real and logical explanation of why there are no antibodies to coronavirus after an illness or direct contact with infected people. T-lymphocytes are responsible for the destruction of their own affected cells, but they also start the chain that starts the production of antibodies. The cells of the immune system, which live much longer than antibodies, are presumably a function of saving the body's resources. He no longer has a reason to engage in the production of the same amount as in the period of contact or illness. However, the information is fixed in T-lymphocytes, and they will be able to quickly activate mediators to re-launch the counteraction mechanism.

Some scientists believe that a decrease in the number of antibodies does not mean a decrease in resistance. In a secondary collision with the coronavirus, the immune response is triggered by T and B lymphocytes. They also consolidate the immunity obtained as a result of the introduction of the vaccine, applying it when a threat appears.

Similar results were obtained at the Swedish Karolinska Institute, but already when studying a much larger number of people. Published data from a survey of citizens who recently returned from Northern Italy show that the number of people with T-lymphocytes detected is about 2 times more than those who have antibodies to COVID-19.

Scientists from different countries, working in parallel in the study of the peculiarities of the human immune system in countering coronavirus, came to one conclusion: to determine whether there is a risk of contracting a dangerous infection again, there are not enough testing systems available to doctors. They are focused on the level of antibodies, which varies for various reasons - from the time of contact with the sick to the time of day. At the same time, they recall that T-cell immunity in patients with other types of coronavirus persists for several years.

Outcomes

1. T-cell immunity is a likely explanation for the lack of antibodies in those vaccinated or recovered.
2. Memory cells start a chain of reactions upon new contact.
3. They can store information for a long time.
4. Experience shows that immunity against other strains of the coronavirus lasts for several years.