Covid -19 : An Enigma for researchers

Coronaviruses were first identified as human respiratory pathogens, in the year 1965, and were known to demonstrate very high rate of mutation. Coronaviruses are enveloped (+) RNAs, that replicate in the cytoplasm. To deliver their nucleocaspid into the host cell, they rely on the fusion of their envelope with the host cell membrane. The spike glycoprotein (S) mediates this entry of the virus and acts as the primary determinant of cell tropism and pathogenesis. Glycoprotein (S) is classified as a class I fusion protein and is reponsible for binding to the receptor on the host cell, whilst mediating the fusion of the host and viral membranes. This is a process driven by major conformational changes of the S protein. On more technical terms, Corona viruses are the containers of the largest ssRNA genome of 33kb. Structurally, coronaviruses are enveloped viruses with round or pleomorphic virions which are 80 to 120 nm in diameter

This 1st generation of coronaviruses could not survive for long, owing to the host resistance. However, in 2002, new strains of these coronaviruses emerged. These strains of Coronaviruses had very similar genome sequences, and had been isolated from animals sold at markets, in China, where the first SARS cases had appeared. Antibodies to these viruses were found in people in China and some bat species. This small outbreak of corona can be consideed as one due to the 2nd generation of Corona viruses.

Finally, the Coronavirus outbreak of 2020-this outbreak had presented itself in the form of pneumonia of an unknown etiology, in Wuhan, China. This is named as SARS-CoV-2. It can be implied that recombination could have occurred, either by viral-viral or viral-host genes committing acts of “molecular piracy” to invade vertebrates and render them immunocompromised. This pandemic begets an extensive line of research by the world’s brightest to solve this enigma, consequently putting an end to it.