How long is one immune after contracting Corona and having already recovered? After researchers discovered some time ago that the antibodies disappear after a while, a new study shows that anyone who has been infected with Corona could even be immune to the virus for life. How does this astonishing result come about? The background.
People who have recovered from Corona may take a back seat in the vaccination priority in Germany for the time being – because they have usually already formed sufficient antibodies against the virus and are thus protected against Sars-COV-2 for at least a period of about six months.
Until now, however, researchers have assumed that the immune protection wears off again after a while, even in those who have recovered. Several studies have shown this: In those affected, the number of antibodies dropped rapidly after a while.
Corona recovery: Antibody levels drop slowly
A new study goes deeper into the analysis. According to it the antibodies sink indeed. However, the researchers no longer assume that there is a lack of immune protection.
A team of researchers at Washington University School of Medicine in St. Louis conducted a study with 77 subjects who all contracted corona about a year ago and had a mild course. In the course of the study, blood was drawn from the subjects one month after infection and then three more times at intervals of three months. The result: the antibody level dropped, but the process slowed down steadily.
Immunity in recovered patients: “Misinterpretation of data”
Ali Ellebedy, one of the authors of the study, told the media, “There was a misinterpretation of the data. It’s normal for antibody levels to drop after an acute infection, but they don’t go to zero, they stay at a plateau.”
COVID gene-naive: A lifetime of immunity because of cells in the bone marrow?
What also makes the study so interesting is that in a total of 18 samples analyzed, antigen-specific plasma cells were still found in the bone marrow almost a year after infection. They are capable of producing new antibodies against the coronavirus when needed. And they do so for a lifetime. In people who have recovered and have a mild course of the disease, it is quite unlikely that the infection will recur.
Ali Ellebedy assumes that the immune cells can produce antibodies against Sars-COV-2 for a lifetime. This is “strong evidence of long-lasting immunity,” says the expert. Now the physician wants to test how it behaves in convalescents with a moderately severe and severe course.
Nevertheless, the “booster vaccination” will probably not be dispensed with for the time being in convalescents with a mild course until the duration of immunity after a Corona infection in convalescents has not been conclusively clarified.