Rumors about COVID-19 reinfections have been circulating for months, and it’s hard not to worry, because patients who seem to recover from the virus suddenly test positive again, sometimes months later. They are rare, and doctors believe they can be removed after a few probable scenarios: defect testing, if the virus hangs as “clogged” in the body, only to be re-examined later.
It is true that scientists are still studying the response of our immune system to coronavirus infection. As with many things during this pandemic, there are many things we do not know, especially when it comes to immunity – how long it lasts, what it looks like in our bodies, and how that plays into the idea of herd immunity. . What rumors have surfaced is good news on this front: Scientists are optimistic that infected people will have COVID-19 immunity in the long run. “All pieces are there to have a fully protective immune response,” said immunologist Marion Pepper, University of Washington, PhD, The New York Times in an article on long-term immunity. There is some science to getting through first, but carry with us – it’s important.
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Coronavirus antibodies are the first line of defense
Most of the news about immunity focuses on antibodies, proteins produced by B cells (more on that later) that protect your body against pathogens. COVID-19 antibodies confer immunity, but the question is how long will it last – and science does not yet give us a concrete answer. Current research shows that antibody levels drop within two to three months after infection, but doctors have insisted that this is a fairly normal immune response. “This is a famous dynamic of how antibodies develop after infection,” said Michael Mina, MD, PhD, an immunologist at Harvard University, in a separate New York Times article on COVID-19 “reinfections.” “They go very, very high, and then they come down again.” This does not necessarily mean that the body is defensive against the virus.
Another important point: scientists do not know what anti-antibody level immunity to COVID-19 confers. “Even small amounts of antibodies can potentially still be protective,” said Mala Maini, MD, PhD, a viral immunologist at University College London, in an interview with Nature. In that case, even low levels of antibodies, such as those found in patients months after infection, could still provide some protection. And for the record, it is not only acute COVID-19 disease that can produce these lasting immune responses – some studies report that even mild COVID-19 infections can do this.
T cells and B cells may provide long-term protection
Antibodies are not the only form of protection: T cells are an important type of white blood cell that scientists look for. T cells can be divided into a few different groups: the first type, CD4 helper T cells, identify pathogens in the bloodstream and, if they find one, ask B cells (another type of white blood cell) for it. begin process of antibody to treat the virus. Another type of T cell, called CD8-killer T cells, identifies infected cells through a different process and kills them on the spot.
That these cells help fight an active infection, but what do they have to do with COVID-19 immunity? For starters, both B cells and killer T cells have the potential to mature into longer lasting forms of protection. B cells can become plasma cells that continue to produce antibodies for a few weeks, then move to the bone marrow for long-term protection, or they can morphine into memory B cells, which are part of the ‘surveillance system’, according to Medical news today. When your body is infected again, the B cells of the memory remember the virus and flag you down to a helper T cell, which can restart the whole production process of antibody. Killer T cells do something similar by turning into memory CD8 T cells, which “provide fast and long-lasting responses” when the virus returns.
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For immunity, the good news here is that plasma cells, memory B cells, and CD8 T cells for memory are all meant to stick and protect the body for a long time, and to separate them from the antibodies that weigh if the infection is taken care of. For COVID-19 specifically a recent study in Sel isolated T cells from the blood of long-recovered patients and found that they actively responded to the presence of coronavirus pathogens, replicating in a protective line of defense. Notably, coronavirus-specific T cells were also found in the blood of people who were exposed but tested negative in an antibody test – meaning that asymptomatic people also have some protection, even if they no longer produce (and positive tests for) Antibodies. Smita Iyer, PhD, an immunologist at UC Davis, described such results as “very promising” in the NEW immunity article. “This requires some optimism about herd immunity, and potentially a vaccine,” she went on to add, adding that this study shows evidence that “you can still get lasting immunity without suffering the effects of infection.”
Antibodies themselves can also help us determine whether B and T cells are attracted to the body. Specifically, the fact that they are still present months after infection (as we did earlier) suggests that B and T cells persist, make infectious antibodies, and continue with their tasks. “Things are really working out the way they should,” said Deepta Bhattacharya, PhD, an immunologist at the University of Arizona, in the NEW article.
Can you become immune to COVID-19?
To definitively prove immunity to COVID-19, scientists will need immediate evidence that humans can fight the virus after a second exposure. We have not yet, although in two small studies, rhesus macaques were immune to the virus after being exposed once. All in all, at the moment the signs are good, showing evidence that our bodies can remain immune to the virus for at least a few months and potentially longer.
POPSUGAR aims to provide you with the most accurate and up-to-date information about the coronavirus, but details and recommendations regarding this pandemic may have changed since publication. For the latest information on COVID-19, please check with WHO, CDC, and local public health sources.
