Nature: In the face of the new coronavirus mutation, the body's immune system is constantly coping with evolution!

To date, the Severe Acute Respiratory Syndrome coronavirus has infected more than 98.8 million people, resulting in more than 2.1 million deaths, in addition to the United Kingdom, South Africa and other regions have been found in the new coronavirus mutant strains.
severe outbreak, countries have developed and approved a variety of vaccines against the new coronavirus.
for patients infected with the new coronavirus, the body produces neutral antibodies produced by the immune system that protect them from infection.
but how long does the immune system's antibody activity against SARS-CoV-2 last? Will the quantity and quality of B cells decline? Can I identify new coronavirus that responds to mutations? These are still unknown.
recently, a team of researchers from Rockefeller University and mount Sinai's Icahn School of Medicine published a study in Nature entitled Evolution of antibody immunity to SARS-CoV-2, which found that patients were infected with SARS-CoV-2. After 2 6.2 months, although the body fluid and active antibodies significantly decreased, but the memory B cells in the evolution of somogenic cell super-mutation, expressed with enhanced effectiveness and resistance to RBD mutation antibodies, solibo immunity has been developing.
To study long-term antibody immunity in patients infected with SARS-CoV-2, the researchers analyzed blood-to-antibody levels and memory B cell characteristics in 87 COVID-19 patients at 1.3 and 6.2 months after infection.
enzyme-linked immunosorption (ELISA) and automatic serological assays found that between 1.3 and 6.2 months, anti-RBD (new coronavirus pyrethroid protein binding domain) and anti-N (nuclear protein) antibodies in the blood decreased significantly, and the decline of each antibody was inversely inversely compared to the initial antibody level.
The use of HIV-1 false viruses containing SARS-CoV-2 prickly protein to measure plasma melium activity was found to have a 5-fold decrease in the meso-antibody titration of the new coronavirus at 6.2 months compared to 1.3 months, indicating that 6 months after SARS-CoV-2 infection, there was a significant decrease in the number of moderately active antibodies in the patient's body, but were still detectable.
Anti-SARS-CoV-2 plasma antibody dynamic memory B cells are differentiated by B cells in the immune system, the antigen has a specific recognition ability, when the antigen secondary infection of the body, memory cells can directly multiply, differentiate to produce plasma cells, and produce antibodies, binding to antigens.
analysis of SARS-CoV-2 memory B cells in patients found a small but significant increase in the proportion of memory B cells of IgG antibodies expressing anti-RBD in the memory B cell population between 1.3 and 6.2 months.
antibody sequences against SARS-CoV-2 RBD, the researchers also found that memory B cells at 1.3 and 6.2 months showed updates in monoclonal antibody species and evolution of antibody sequences, indicating that the immune system continued to optimize its antibody immune response to the new coronavirus between 1.3 and 6.2 months after infection.
evaluated the re reactivity of 122 representative antibodies to RBD at these two points in time and found that 115 of them were able to bind to RBD and that the EC50 (semi-maximum effect concentration) of the antibody increased significantly at 6.2 months.
anti-SARS-CoV-2 RBD monoclonal antibody reacts, how resistant are these antibodies to virus mutant strains? The researchers measured their binding effects to the wild RBD and mutant RBD of SARS-CoV-2 and found that 83% of the antibody clones that occurred at both points in time were cloned with the mutant RB at 6.2 months. The overall binding of D increased, and in E484 (The mutation position of the Brazilian and South African mutants), Q493, N439, N440 and R346 these RBD mutation amino acids were the most significant.
Analysis of the meso-wide range of antibodies that bind to the mutant RBD found that, in addition to having a stronger melision force, the antibodies expressed by evolutionary memory B cells also had a higher median breadth, and some antibodies were able to mediate more than one viral variant.
Anti-SARS-CoV-2 RBD monoclonal antibody's mesoactive activity finally, the researchers analyzed that the continuous evolution of antibodies may be through antigens in the form of immunopsyconds retained on the surface of fable dendrites for a long time, so that the B cells in the center of the birth produce sorocyte super mutations and constant selection occurs, the human tissue residual low-level viral proteins may also be as antigens to further promote antibody evolution.