Scientists are still trying to establish how long the immunity to COVID-19 lasts, as it is important for vaccination and crowd immunity.
COVID-19 antibodies in donated blood plasma begin to fall about three months after infection and disappeared completely within three to four months.
During the study, weekly samples were taken from 15 volunteers (11 men and four women) who volunteered to participate in experimental treatment with blood plasma of COVID-19 patients.
The concentration of antibodies began to fall on average 88 days after infection with the coronavirus, and over the next three weeks thereafter, the concentration of detectable antibodies decreased by about half. Three to four months later, these antibodies were practically not detected in the samples.
Note that in the summer, this group showed that those who underwent COVID-19 in a mild or asymptomatic form can lose their antibodies within a hundred days after infection.
It is assumed that the vaccines under development will also have a short-term effect, but the scientists reassure that, firstly, the results they obtained are only for antibodies in those who have been ill, they have not studied the T-cell immune response. Second, the candidate vaccines elicit higher antibody levels than the disease. Third, vaccination leads to a different response mechanism.
The results of the study were published in the journal Blood, reported by Medical Xpress.