03:42 PM
Wednesday 14 October 2020
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Agencies:
A new study reported that people who survive severe cases of the new coronavirus may have immunity that lasts for a longer period.
The researchers found that the levels of antibodies remained high in patients who were hospitalized with a “Covid-19” infection for up to four months.
Moreover, these antibodies are bound to other equivalent antibodies that kill the virus upon contact, and prevent it from re-infection, according to Russia Today.
The team, from Harvard Medical School and Massachusetts General Hospital, says the results provide evidence for measuring levels of antibodies as a tool to track the spread of “Covid-19” within a community.
Scientists have long known that the immune system produces antibodies after someone contracts the Coronavirus.
However, “there is a large knowledge gap regarding the duration of these antibody responses,” said lead investigator Dr. Richelle Charles, a researcher in the Department of Infectious Diseases at Massachusetts General Hospital.
In the study, published in Science Immunology, the team analyzed blood samples from 343 patients with “Covid-19”.
Most of the patients had severe cases, requiring hospitalization of 93% of them.
All samples were taken for up to four months, after the patients began to experience symptoms such as coughing, fever and shortness of breath.
The researchers separated the plasma from the blood and swabbed it in dishes containing the receptors that the virus uses to enter and infect cells.
Next, they examined how the different types of antibodies in the plasma bound to the receptor. One of the antibodies, immunoglobulin G, is a protein that the body produces in the late stages of infection.
IgG levels remained elevated four months later, and were linked to equivalent protective antibodies also found in the blood.
This means that it is very likely that people will be protected for that period of time. We have shown that the main antibody responses to “Covid-19” are still in place, Charles said.
The team also found that other antibodies, specifically immunoglobulin A and immunoglobulin M, have relatively short-lived responses.
The results showed that it remained at low levels, for a period of no more than two and a half months, on average.
The researchers say the reason for this is that these two duplicate bodies are usually made by the body a few days after injury, and are not known to be long lasting.
Charles added: “We can now say that if the patient has had IgA and IgM responses, then it is likely that he has been infected with the virus within the past two months.”
Knowing how long immune responses take, particularly IgA and IgM, can help public health experts track the virus more closely and accurately.
Lead author, Dr. Jason Harris, a specialist in pediatric infectious diseases at Jason Harris College of Medicine, said: “There are a lot of infections in the community that we don’t catch through testing during acute infections, and this is especially true in areas where access to testing is limited. “.
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