Researchers at Rockefeller University, New York have found that coronavirus immunity in people who recover from the virus is very strong. They found that the immune system of the person in addition to remembering the virus also produces improved quality antibodies, enabling the body to provide a potent and swift defense incase the virus attacks again. The study has not been peer-reviewed or published in a journal yet.
A senior author of the study Michel Nussenzweig said that the expectation is that people who recover from the virus should be able to produce a quick antibody response and also resist infection. It is still unclear however that how long the coronavirus immunity might last but Nussenzweig believes that the immune system’s memory may potentially protect against the virus for years. The findings from the study may be the reason why verified cases of coronavirus reinfections are very rare.
When the coronavirus attacks a person the immune system of the body starts an attack on multiple fronts. At one front the protection is provided by T cells, which locate and destroy the cells which are infected and thus prevent the spread of the virus in the body. The second form of protection is provided by B cells, the function of whom is to release antibodies in the blood. The released antibodies then attack the virus and stop it from attacking cells in the body.
When a person recovers from the virus the immune system of the body stands down, however, it remembers the infection by storing those memory B cells and memory T cells. If and when the virus attacks again those two are called immediately into action. Many studies in the recent past have shown that the first wave of antibodies produced by the body against coronavirus vanish quickly within a few months, which raised concerns that the coronavirus immunity may quickly vanish.
The researchers from Rockefeller University studied 87 patients of the virus and confirmed that the antibodies vanish and reduce to around 20% of their peak level within six months. However, they believe that it won’t matter too much. This is because when the researchers from the US were examining the memory of the immune system, they found that the memory B cells had become more potent six months after the infection. The body could unleash these improved antibodies within days after the re-infection instead of taking weeks to develop as seen in primary infection.
The researchers further showed that very small particles from the virus or protein fragments from virus particles stayed in the intestine of the patient and also apparently helped in maintaining the memory of the immune system. These small particles from the virus are thought to be harmless.
Nussenzweig said that it can be concluded from the study that people who have contracted the virus have continuing memory responses of the B cell after six months of being infected along with antibodies capable of neutralizing the virus. Meaning the antibodies can wipe out the virus before it can take hold. He further added that it is not known how long the protection will last but it could last for years.
Professor of immunology at Imperial College London Charles Bangham said that the study suggests that there is a good chance that when a person gets exposed to the virus for the 2nd time, his coronavirus immunity will be brisker. He said that it is not proved yet if the strong immune response will be protective against the virus but it could have some benefits.
Professor of Immunology at the University College London Arne Akbar said that the findings made by this study are very good news for every person who has already been exposed to the coronavirus. According to him the immune system of a person is like an army that stands down during peacetime but remains ready for any future attacks. He further added that the army should be regenerated quickly and that’s what the researchers have found in the study.