Rather, viruses need to invade and take over host cells to replicate. But a virus can't break into just any cell in the body. Instead, one of its proteins will bind to another protein — akin to a key fitting into a lock — which then allows the virus to hijack certain cells.
With this outbreak, the coronavirus' so-called spike protein primarily fits "locks" that are present on lung cells, which is why COVID, the disease it causes, is mainly a respiratory illness. Once the invasion takes place, the cell in essence is transformed into a factory that churns out hundreds and hundreds of copies of the virus, based on instructions encoded in its genetic material — RNA, or ribonucleic acid, in the case of the coronavirus.
The human body has evolved defense systems to protect against these kinds of infections. First, cells have a built-in alarm system to detect viral invaders. The presence of an intruder triggers what's known as an innate immune response, which can involve the host cell releasing a protein that tries to interfere with the virus' replication or can involve the immune system trying to shut down the compromised cells.
The work of these reinforcements to try to defeat the virus is typically what causes the symptoms of a viral infection — in other words, it's at this point when a person may come down with a fever and start to feel sick. But viruses are sneaky, Glaunsinger said, and they are often able to fly under the radar and cause a lot of damage before any alarms are triggered and any reinforcements are called in. By the time an immune response kicks in, it's often too late.
When the immune system is finally triggered, it can also kick into overdrive, causing what's called a cytokine storm, which is thought to be the root of some of the most severe coronavirus cases.
For more in the world of tech and science , keep reading Indiatimes. McCarthy, M. Scientists identify antibodies that can neutralize omicron. Videos News India. Latest Stories. Mutual Funds. Worth X. Science And Future. But why are they antibodies so important? And if not, why not? You may have heard news reports explaining that antibody tests are key to slowing the infection rate. You may also have heard medical experts warn that having the antibodies may not guarantee immunity against a second COVID infection.
Here, Jonathan Fogle , associate professor of microbiology and immunology at North Carolina State University, explains what antibodies are and why they are so important:. Antibodies, also known as immunoglobulins Ig , are specialized proteins that bind to a uniquely shaped object—called an antigen—that is found on the surface of a pathogen. These pathogens can be things such as bacteria or viruses. Antibodies are produced by B lymphocytes, known as B cells, which are specialized white blood cells of the immune system.
B cells have antibodies on their cell surface that allow them to recognize anything foreign. When they encounter a pathogen, the B cells transform into plasma cells, which start producing antibodies that are designed to bind to an antigen that is specific to this pathogen.
This protects us in two main ways. First, antibodies can bind to antigens on the outside of the pathogen to stop it from entering our cells. Second, by binding to antigens on the pathogen, antibodies also signal other white blood cells known as phagocytic cells, which engulf and destroy the pathogen.
So, in short, antibodies can both neutralize a virus and mark it for destruction. Antibodies form part of our adaptive immune response, which is a refined, targeted response to a specific antigen. The first time we encounter a virus, some of our B cells become plasma cells, but others transform into memory B cells. The first time someone is infected by a specific pathogen, it normally takes a few weeks to manufacture antigen-specific antibodies.
But if we are re-exposed to the same pathogen, the production of antigen-specific antibodies is rapid, usually within the first day. Vaccines usually contain pieces of the pathogen that can stimulate our immune systems to manufacture antigen-specific antibodies and produce memory cells.
So if we are exposed to this pathogen again, we are already prepared to respond very quickly. This novel coronavirus is new to the human population—we have never been exposed to it before—so there are many unknowns about how we respond to it.
Across any population, there is a high degree of individual variability in our antibody responses to a pathogen in the amount, type, and quality of antibodies that we make. Some people make many high-quality antibodies that are very good at recognizing the relevant antigen and binding to it. If this happens, the virus is rapidly bound by antibodies and eliminated before it can even cause an infection.
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