“Those who have fallen slightly ill with Covid-19 have an immune cell capable of producing antibodies against the virus for the rest of their life” confirmed a study published by the prestigious Nature.
In people infected with SARS-CoV-2, the level of antibodies / proteins capable of blocking the virus begins to decrease after four months. What is important to know is whether, despite this deficit, the patient has developed a complete immune response. That is, an answer that guarantees the creation of white blood cells with memory capable of remembering and eliminating the virus many months and even years after the first infection.
The Nature study looked at 77 patients with mild or moderate disease.
In most of them the antibodies decreased rapidly after four months, but then the reduction was slower and these molecules are present in the blood for up to 11 months after infection.
Furthermore, the work was the first to analyze the presence of long-lived plasma cells in the bone marrow. These cells are born when a pathogen enters the body so that they can remember different characteristics of it.
For Covid-19 it is the S protein that the virus uses to infect cells.
After infection, these immune cells move into the bone marrow and remain there in a latent state. If the virus reappears, the cells return to the bloodstream and start making antibodies against the virus again. The vast majority of patients. 15 out of 18 were able to generate these immunizing cells.
Ali Ellebedy, an immunologist at the University of Washington School of Medicine and lead author of the study, confirmed that “long-lived plasma cells can last a lifetime. These cells will continue to produce antibodies forever. “
The presence of antibodies does not always mean that the person is “immune” to reinfection, although this is very likely to be the case.
The scientist also pointed out that “if the antibodies produced by long-lived cells are not enough, the immune system activates the memory B cells that can produce even more antibodies.” Immunity against SARS-CoV-2 mediated by different types of lymphocytes and immune cells most likely lasts for years.
A mechanism that is also seen in other diseases such as smallpox that generate defenses even after 50 years.
The only open question is whether this permanent immunity can also apply to any variants of the disease. According to the researcher, it all depends on how much the genetic sequence of the virus changes but it is reasonable to think that this type of cells can provide permanent immunity.
Another question answered by the study is that it seems clear that there is no need to vaccinate someone who has already had the disease. Many health experts confirm that there is no need for a third dose as Pfizer and Moderna say. It is essential to vaccinate everyone for the first time.
But the discussion remains open and complicated. And above all, the billionaire vaccine business seems to have a big say in the matter.