The body’s protective antibodies against the novel coronavirus target a different part of the virus in severe cases of COVID-19 than they do in mild forms of the disease, and severe side effects within several months of the disease, a new study says.
According to the scientists, including those from Stanford University in the US, the findings shed new light on the links between the course of the disease and the patient’s immune response.
The research, published in the journal Science Immunology, found that people with COVID-19 have lower levels of antibodies that target the spike protein the virus uses to enter cells human than those targeting proteins of inner shell of the SARS-CoV-2 virus.
“This is one of the most comprehensive studies to date on the antibody immune response to SARS-CoV-2 in humans across the full spectrum of disease, from asymptomatic to lethal,” said Scott Boyd, co-author of the study from Stanford University. “We evaluated several time points and sample types, and also examined levels of viral RNA in patients’ nasopharyngeal swabs and blood samples. This is one of the first big pictures of this disease, ”said Boyd.
In the study, the scientists studied 254 people with asymptomatic, mild or severe COVID-19 who were identified either through routine tests or occupational health screening at Stanford Healthcare or who came to a Stanford Healthcare clinic with symptoms. COVID-19. According to the scientists, 25 of the people with symptoms were treated as outpatients, 42 were taken to the hospital outside the intensive care unit and 37 were treated in the intensive care unit.
The study noted that 25 people died in the study of the disease.
From a study of patient samples, the scientists said that antibodies that recognize and bind to the spike protein prevent the virus from invading the cells. However, they said that the antibodies that recognize other viral components are likely to inhibit viral transmission. The researchers evaluated the levels of three types of antibodies – IgG, IgM and IgA – in the patients. They estimated the proportion of antibodies targeting the viral spike protein or the inner shell of the virus as the disease progressed and the patients recovered or recovered. become ill.
“We found that the severity of the disease is related to the ratio of antibodies that identify areas of the spike protein compared to other non-immune viral targets,” Boyd said. “Those with moderate illness tended to receive a higher proportion of anti-spike antibodies, and those who died from their infection had more antibodies that identified other parts of the virus,” he said.
Although the study identified trends among a group of patients, the scientists said that there is still a big difference in the immune response that individual patients put up with, especially those with severe disease.
They believe that antibody responses tend to be the only determinant of a person ‘s result. “Among people with a very serious illness, some die and some recover. Some of these patients have a strong immune response, while others have a more moderate response, ”said Boyd.
“So there’s a lot more going on. Other branches of the immune system are also involved. It is important to note that our results identify correlations but are not causal, ”he said.
The scientists also found that people with asymptomatic and mild illness had lower overall levels of antibodies than those with severe disease. IgM and IgA levels decreased steadily in patients after recovering to low or indeterminate levels over a period of about one to four months after the onset of the symptom, and IgG levels dropped significantly.
“This is completely consistent with what has been seen with other coronaviruses that circulate regularly in our communities to cause the common cold,” Boyd said.
(This story was published from a wire group without text changes. Only the headline was changed.)
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