When a user is inflamed with a virus, their body produces antibodies to fight infection. After healing, antibodies can remain in the user’s blood plasma for months or even years. In convalescence plasma treatment, other newly ill people, in this case with coronavirus – get plasma from a recovered user in the hope that they have their own ability to fight the virus and restrict its severity.
“While many clinical trials are being conducted to better understand whether convalescent plasma is clinically favorable for the COVID-19 remedy, a key question is when is it most effective to collect plasma from a donor based on the presence of antibodies that help fight the virus, “said Renée Bazin, Ph. D. , of the Héma-Québec blood center (Canada) and author of the study. “Based on our findings, antibodies to the new coronavirus do not last forever. “
This small study, conducted with 282 COVID-19 plasma donors in Quebec, Canada, followed 15 adults (11 men and four women) who were diagnosed with COVID-19 and then recovered. While symptoms ranged from mild to severe, none of them donors were hospitalized for COVID-19 infection, participants donated their plasma four to nine times, with the first donation being made between 33 and 77 days after the onset of symptoms and the last donation between 66 and 11 four days.
Dr. Bazin said this test is one of the first longitudinal tests to show that other HIV-positive people, i. e. they have produced antibodies opposed to the virus that causes COVID-19, HIV-negative, which means there are no detectable viruses. Decreased antibodies over time do not appear to be similar to the number of times a user has donated blood plasma, but is due to the time elapsed since infection and a decrease in the immune response based on herbs. donors showed a minimum of antibodies at the same time, approximately 88 days, and some of the detectable antibodies were minimized in 21 days.
“Antibodies disappear quickly, so other people who are recovering from COVID-19 and need to donate blood plasma should not wait too long once they are eligible to donate,” Dr. Bazin said.
For this analysis, the study team focused on antibodies targeting a virus target called receptor binding domain (RBD). RBD is a protein on the surface of the virus that acts as a key and joins ACE-2. receptor on the cell surface, in turn, opening a door through which the virus enters and infects the cell, but the immune formula can expand RBD antibodies that inhibit the protein’s ability to integrate and open the door to the ACE-2 receptor, preventing the virus from entering the cells.
“Based on our results, clinicians preferably use plasma that is collected shortly after the onset of symptoms from a donor and check for the presence of antibodies before administering a donor plasma to a patient,” said Dr. Bazin.
He noted that nearly 7% of the original 282 donors had no detectable antibodies at the time of their first donation and that this ratio doubled when donors who waited more than 11 to 12 weeks after the onset of symptoms before making a donation.
Of course, understanding the drop in antibodies after an herbal infection with COVID-19 has practical programs not only to tell policy when convalescent plasma is the most effective (i. e. , before the immune reaction begins to decrease), but can also have implications for seroprevalence studies that evaluate how many others in a network have antibodies to the virus. “According to our results, if antibodies are minimized 3 to 4 months after a peak infection, we would possibly underestimate the prevalence of infection in communities or populations,” Dr. . Bazin.