5:00 PM
Saturday 26 December 2020
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Books – Sayed Metwally
A new study, in which scientists from Queen Mary University of London, participated in, found evidence of protective immunity in people up to four months after a mild or asymptomatic infection with the Coronavirus.
The study, published in the journal Science Immunology, analyzed the antibody and T-cell responses of 136 health care workers in London who had mild or asymptomatic COVID-19 infection, dating back to March 2020, according to the “medicalxpress” website.
The team, which includes researchers from Queen Mary, Imperial College London and University College London, found that 89 percent of healthcare workers analyzed carried neutralizing antibodies 16-18 weeks after infection.
The researchers discovered that most of them also contain T cells that are able to recognize multiple different parts of the virus, but the two responses did not always persist, as some individuals showed T-cell immunity but no evidence of antibodies, and vice versa.
Joseph Gibbons, a researcher at Queen Mary, said: “Our study of SARS-CoV-2 infection in healthcare workers in London hospitals reveals that four months after infection, about 90 percent of individuals have antibodies that block the virus, and the most encouraging thing is. That in 66 percent of health care workers we see levels of these protective antibodies are high and that this powerful antibody response is supplemented by T cells that we see interacting with different parts of the virus, this is good news, meaning that if you are infected, there is a good chance. Because you have developed antibodies and T cells that might provide some protection if you encounter the virus again. “
Mismatched immune responses
Since the start of the epidemic, scientists around the world have worked to understand how our immune system protects us from SARS-CoV-2, and how long this protection lasts, and much of this research on protective immunity has focused on the different roles of B cells, which make antibodies, and T cells. These are white blood cells that work in many different ways to help protect against viruses.
In this study, the researchers showed that while protective antibody responses were usually complemented by a T-cell response, more than half of the healthcare workers had mismatched antibodies and T cell responses, and did not produce a T-cell response specific to the proteins on the surface. , A layer of SARS-CoV-2.
They also found that T-cell responses tended to be higher in those with the classic symptoms of COVID-19, while asymptomatic infection resulted in weaker T-cell immunity than symptomatic infection, but equivalent antibody responses.
Reassuring evidence
Understanding how this precise design of immune responses works in people with mild infection or without symptoms is especially important because they represent the largest group affected.
The new study also provides reassurance for vaccination efforts, indicating that even after a mild infection, individuals carry antibodies and T-cell immunity to many parts of the virus, known as episodes, and while new variables emerge, changes to the virus do not necessarily occur within these cells, It is thus hoped that the vast majority of immune recognition will continue without concern.
Dr. Corinna Bed, a research scientist at Queen Mary, said: “Our study in mild or asymptomatic cases gives positive insight into the durability of immunity against SARS-CoV-2 four months after infection, and there is a remarkable number of about 90 per cent. Hundreds of individuals have a common force of strong antibodies that prevent the virus from entering, along with T-cell responses to different parts of the virus to interfere with its survival, this is an important finding because symptoms of COVID-19 are mild or even not appearing at all, are very common. The abundant immune responses also provide hope for the long-term effectiveness of vaccines. “
Shane McKnight, professor of viral pathology at the Blizzard Institute in Queen Mary, added: “Finally, here is evidence of the persistence of the antibodies and T-cell immunity against SARS-CoV-2 that so many have been waiting for. this study”.
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