Letter to Editor
Department of Molecular Medicine, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
Clinical Tuberculosis and Epidemiology Research Center, (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
Department of Immunology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Coronavirus disease 2019 (COVID-19), caused by a member of the Coronaviridae family (SARS-CoV-2), was initially reported in Wuhan, China in late December and spread rapidly around the world, reaching a pandemic level (1). This disease has been diagnosed in almost 4.44 million people globally, resulting in more than 302,000 deaths until 15 May, 2020 (2). In Iran, a total of 115,000 confirmed cases of COVID-19 were reported until May 2020, with a fatality rate of 5.118%. Coronaviruses are enveloped positive-stranded RNA viruses with an approximate size of 80-120 nm. They contain the longest viral RNA genomes of all RNA virus families (3). The whole genome sequence of this novel virus contains 29,903 nucleotides. SARS-CoV-2 is closely related to bat-derived SARS-like coronaviruses, sharing 79% nucleotide identity with SARS-CoV (4, 5). Also, viral capsid proteins, including spike glycoprotein (S protein), play an important role in the cell entry and tropism in patients with COVID-19 (6). Overall, coronaviruses use a variety of receptors to enter the cells. Recent evidence shows high homology between SARS-CoV and SARS-CoV-2, as SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) as its receptor, similar to SARS-CoV (7).