Researchers at the Tel Aviv University, Israel, have found that antibodies extracted from the immune system of Covid-19 recovered patients can help neutralise the infection progression due to any Covid strain, including Omicron and Delta. The study may reduce the need for repeated vaccinations and increase the immunity of people at risk.
Image Credits: Pixabay
What are antibodies?
Antibodies are blood protein molecules formed by the immune system in response to or counterattack a specific foreign pathogen or antigen such as viruses, bacteria, etc. They chemically combine with unique molecules that the body identifies as alien in the blood to remove them. Antibodies play a vital role in defending our bodies from disease-causing organisms. They act as the first line of defence and provide long-term protection against pathogens.
How do antibodies work?
When a foreign substance enters the body, the immune system recognises it as alien because the surface of the foreign substance has different molecular composition than those of body cells. The immune system commands antibody production to eliminate the invader. These are produced by specialised white blood cells or B Lymphocytes (B-Cells). When an alien substance binds to B-Cells, this stimulates B-Cells to divide and mature. The antibodies circulate throughout the body and attack the invader by chemically binding to it. Through this process, they prevent disease-causing microbes from penetrating body cells.
How can antibodies curb Covid infection?
Previously, researchers sequenced B-Cells from the patients who recovered from Covid-19 in Israel and isolated nine antibodies from their blood samples. However, they have now found that some antibodies are effective in counterattacking new Covid variants, such as Delta and Omicron. They showed that the antibodies formed in response to the original virus infection work by affecting the different sites of the virus’s surface.
Image Credits: Pixabay
The most effective antibodies were those that bound to the virus’s spike protein on the surface. It is the same place where the spike binds the cellular receptor ACE2, a proteinaceous receptor for SARS-CoV-2 found on the surface of many cells, including human cells.
“In the current study, we proved that two other antibodies, TAU-1109 and TAU-2310, which bind the viral spike protein in a different area from the region where most of the antibodies were concentrated until now (and were therefore less effective in neutralising the original strain) are actually very effective in neutralising the Delta and Omicron variants. According to our findings, the effectiveness of the first antibody, TAU-1109, in neutralising the Omicron strain is 92%, and in neutralising the Delta strain, 90%. The second antibody, TAU-2310, neutralises the Omicron variant with an efficacy of 84%, and the Delta variant with an efficacy of 97%,” said Dr Natalia Freund, the study author.
Dr Freund believes that the antibodies’ effectiveness can be related to the virus’s evolution. Every time the genetic sequence of the virus’s spike protein changes where it binds with the ACE 2 receptor. This makes the virus vulnerable to antibodies that are formed after vaccinations. However, the antibodies; TAU-1109 and TAU-2310 don’t bind to the ACE 2 receptor but attach to the spike protein or receptor that does not undergo multiple mutations. Hence, they are more effective in counterattacking more viral variants and can help to fight against Covid infection.
The study results were published in the journal Communications Biology.