Recent advances in the knowledge of coronaviruses with special emphasis on severe acute respiratory syndrome coronavirus 2 (Sars-cov-2)

COVID-19 continues to pose a global public health emergency several months after the first cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (then referred to as novel coronavirus [2019-nCoV]) infection were reported in Wuhan, China. Starting off as local infection, it has now affected most countries devastatingly while taking its toll on millions of people. So far, clinicians and researchers have derived biological understanding and treatment designs to tackle COVID-19 from the recently learned lessons during similar epidemics caused by coronaviruses, namely, SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV). However, COVID-19 has transformed into a pandemic surpassing the previously reported epidemics and requires a targeted therapy approach in addition to synchronized preventive measures. With the advent of new knowledge and developments on the subject of SARSCoV-2 almost every day, an update to the biological understanding of coronaviruses is necessary as well. This article presents a comprehensive review of SARS-CoV-2 biology, COVID-19 epidemiology, and therapeutic approaches for patients along with the major issues of concern. We cover the structure and infection mechanism of SARS-CoV-2 known till date, along with the common pathological findings and immune responses in patients. We also review the patterns of disease epidemiology in India and worldwide, the current therapeutic modalities as well as the possible strategies of prophylaxis and treatment that may be used for COVID-19 patients in the near future. Finally, we discuss a few challenges put forth by this pandemic in a developing country like India which need to be addressed immediately.