An exceptional discovery could revolutionize the history of Sars-CoV-2 and ours in fighting Covid-19. One studio of the Washington University di St. Louis, Missouri, has identified a type of immune cells, in bone marrow of patients recovered from Covid, capable of persisting healing beyond 11 months. The study provides evidence that the immunity triggered by Sars-CoV-2 infection will be extraordinarily long-lasting.
Published in the prestigious international magazine Nature come on PubMed, an important research engine of biomedical scientific literature, the paper opens a window to the possibility of getting out of the pandemic faster than we thought.
We knew that antibodies against Sars-CoV-2 tend to decrease over time after healing but in the study “Sars-CoV-2 infection induces long-lived bone marrow plasma cells in humansl” the US researchers explain that they have traced cells , in the body of sick patients, which they survive for a long time (it is not yet known how much but for a long time) and certainly more than the time since the pandemic was declared worldwide. Almost all infections activate this type of cell which is also “ignited” with the Sars-CoV-2 virus. Let’s talk about a particular type of biological unit, very similar to the one that produces antibodies in the first phase of the disease. They are cells located in the bone marrow. Their peculiarity is that they make the antibodies survive in the case of the presence of viruses in general.
In the study, the Missouri scientists tested 77 patients who had developed a moderate form of Covid, trying to analyze how antibody levels, the so-called Iggs, evolved. 18 volunteers also provided a sample of their bone marrow to identify these so-called long-surviving plasma cells. In the case of the people analyzed, the IGGs were present even after 11 months against a decrease in the value of traditional antibodies over time. “People recovering from mild Covid-19 have bone marrow cells that can churn out antibodies for decades, even though the viral variants could dampen some of the protection they offer,” writes the magazine. Nature.
B lymphocyte immunologist Ali Ellebedy led the study, speaking to the British magazine: “A plasma cell is our life history, in terms of pathogens we have been exposed to.”
In the 77 subjects studied in depth, the Sars-CoV-2 antibodies collapsed in the 4 months following the infection, but shortly after this decline slowed down and after 11 months from the infection the researchers could still detect the antibodies that recognized the spike protein of the SARS-CoV-2.
The Ellebedy team of Washington University in St. Louis, Missouri also noted that the same cells are also activated at Pfizer mRNA vaccination. But the persistence of general antibody production, caused by vaccination or infection, does not guarantee lasting immunity to Covid.
The discovery raised an important debate in the international scientific community.
“The implications are that the vaccines will have the same lasting effect,” a Nature Menno Van Zelm, immunologist at Monash University in Melbourne, Australia, talking about those who have not yet contracted Covid and undergo various serums.
“This is a very important observation,” said Rafi Ahmed, an immunologist at Emory University in Atlanta, Georgia. Ahmed’s team had already discovered the existence of these cells that produce special antibodies against viruses in the 1990s. “What is unclear is how long-term antibody levels will look and whether they offer protection,” Ahmed added, referring to even longer lead times, “we are at the start of the game. We are not looking at 5 years, 10 years after the infection ”.