Since the start of the covid pandemic, many terms have become popular in reference to the virus, such as antigens, a word widely used, especially since the rapid coronavirus detection tests began to be sold in pharmacies.
Thus, the term ‘antigen’ no longer sounds strange to anyone, although the exact meaning of the word is not always clear. Basically, an antigen is “any substance that causes the body to produce an immune response against it”.
These can be toxins, chemicals, bacteria, viruses and other substances from outside the body.
This means that the body’s immune system, upon encountering this external substance, does not recognize it and, therefore, tries to fight it, as indicated by MedlinePlus, the National Library of Medicine of the United States.
Therefore, any substance that helps the body to produce immunity against it is also an antigen. That is why these antigens can be used as markers in laboratory tests to identify the presence of a certain substance, as is the case with the antigen tests in pharmacies, which detect the virus.