Covid-19 and Sars: Two corona virus pandemics encountered in the last two decades

Abstract

The New Corona Virus Disease declared by the World Health Organization as pandemics on 11th March 2020, is the third pandemics caused by coronaviruses since the beginning of the 21st century. Other pandemics are Severe Acute Respiratory Syndrome and Middle East Respiratory Syndrome. While the similarity between SARS-CoV-2 and MERS-CoV was 50%, the same between SARS-CoV-2 and SARS-CoV was higher than 80%. With regard to virus classification, those three viruses, causing pandemics belonged to the coronavirus (in Latin: Orthocoronavirinae) sub-family of the Coronaviridae family. The Corona Viruses are enveloped RNA viruses which cause a wide spectrum of respiratory tract infections in human, other mammals or birds. The receptor bound by SARS-CoV and SARS-CoV-2 to penetrate to the host cell is common, namely angiotensin converter enzyme 2 receptor. Corona viruses are shown to bind to the angiotensin converter enzyme 2 receptor on the surface of human cell by means of the spike protein (S protein) being one of the structural proteins existing on its outer envelope. As SARS-CoV-2 is a newly appearing virus, in this compilation we compared the two coronavirus pandemics, i.e. Severe Acute Respiratory Syndrome and the New Corona Virus Disease, encountered in the last two decades. We searched the function of the angiotensin converter enzyme 2 in cells, in which the angiotensin converter enzyme 2 is expressed, similarities and differences of the clinical profile of SARS and COVID-19. Our purpose is to compile the information and experience obtained from the Severe Acute Respiratory Syndrome outbreak with the understanding we gained from the New Corona Virus Disease and to assist in offering new ideas in an effort to prevent this pandemic.