Some mutated species of the Coronavirus family, which is commonly accepted as a disease agent in animals, can also cause diseases in humans. We have witnessed examples of this as SARS in 2002 and MERS in 2011, both of them being severe lower respiratory tract infections. The causative pathogen of the disease, which has become a pandemic (a worldwide epidemic) today, is named the SARS-CoV2 virus, and the disease it causes is COVID-19. It causes serious lower respiratory failure, as in previous examples, and may damage the central nervous system in the early period, unlike the previous ones.
Like other members of the Coronavirus family, this virus has a sheath called the envelope in its fat structure, which has spiky protrusions of its protein structure on its outer surface. Because it looks like a “crown” due to these spiky protrusions, it is referred to as “corona”, meaning crown (figure). The spiky proteins of the SARS-CoV2 virus differ from the SARS virus by 2% and provide much better adhesion to human cells. The virus is a non-living pathogen agent with its nucleic acid chain (a kind of helical amino acid chain that carries genetic codes) in the envelope. The virus can replicate itself, cause damage, and spread only when it infiltrates into another cell. For the SARS-Cov2 virus to infiltrate into cells, its envelope structure must be strong. The virus becomes harmless as oil solvents such as soap or detergent damage the envelope structure. It can remain infectious for only a few days if it cannot infiltrate into the cell provided that its envelope structure is strong. The exposed virus is deformed over time and becomes ineffective. When a sufficient number of SARS-CoV2 enters the human body, the infection begins once the virus clings onto the surface epithelium (a skin-like but much thinner, a single layer of cell covering the inner cavities of our body) and then infiltrates the cell.
