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Recovery the coronavirus may not be equal with patients producing different types of antibodies, a new small study suggests. Researchers found that some patients developed immune cells that stopped the virus from attaching to host cells, some had antibodies that prevent the virus from replications, and others had cells that played a role in immunity.
Additionally, immune cells were in the body at least two weeks after being discharged from the hospital. This suggest that antibodies were maintained for at least that long – welcome news considering little is known about the new virus.
The team, led by Tsinghua University in Beijing, China, say little is known about the body’s immune responses after recovering from the virus and that closing the knowledge gap may speed the development of a vaccine.
‘These findings suggest both B and T cells participate in immune-mediated protection against the viral infection,’ says co-senior author Dr Chen Dong, Dean of Tsinghua University’s School of Medicine in Beijing, China.
‘Our work has provided a basis for further analysis of protective immunity and for understanding the mechanism underlying the development of COVID-19, especially in severe cases. ‘It also has implications for designing an effective vaccine to protect against infection.’
For the study, published in the journal Immunity, the team looked at 14 patients recovered from COVID-19, the disease caused by the virus, and six healthy controls. Eight of the 14 were recently discharged and the other six had been discharged two weeks prior.
Scientists collected blood samples and looked at the levels of two antibodies: immunoglobulin M (IgM), which are the first to appear, and immunoglobulin G (IgG) antibodies, which are the most commonly found. In comparison with the control group, all 14 patients had higher levels of both IgM and IgG antibodies.
The team says this shows coronavirus patients do have an immune system response to the virus, which is maintained for at least two weeks. Additionally, five of the newly discharged patients had higher levels of T cells, types of immune cells, that a signaling molecule that plays a role in immunity. Three of the patients had T-cells that secreted a molecule that protects the virus from replicating within the body.
Seven of the eight newly discharged patients had at least ‘detectable’ levels of the molecule that prevents the virus from attaching to receptors on human cells when trying to invade them. Some had all three and others had just one of the antibodies. The team says it plans to confirm its results in a future study involving a larger number of COVID-19 patients.
DailyMail