Coronavirus Disease (COVID-19) Pandemic: A Race Against Time (original) (raw)

2020, Current Topics in Medicinal Chemistry

The emergence of a novel coronavirus, 2019-nCoV in Wuhan, Hubei province of China, at the end of 2019 and its rapid spread across the world has been alarming. This is the third outbreak of coronaviruses in the recent past after the SARS-CoV outbreak in 2002 and MERS-CoV in 2012. SARS-CoV2, a zoonotic virus that has originated in bats and jumped species from animals to infect humans, spreads mainly through human to human transmission from respiratory droplets on sneezing or coughing. This virus was named 2019-nCoV and the disease caused by it is referred to as COVID-19. The current 2019-nCoV outbreak was declared a Public Health Emergency of International Concern by WHO on 30 th January 2020. The gravity of the situation can be gauged by the fact that the number of cases has soared to 179112 cases and 7426 deaths and it has spread to 170 countries and territories claiming 8,272 lives [1]. WHO has declared the current outbreak of Coronavirus as pandemic on March 11, 2020. This is the first pandemic caused by a Coronavirus, and it has forced public health experts and policymakers to swing in action to control the situation. Symptoms include fever, dry cough, fatigue, pains, nasal congestion, runny nose, sore throat, shortness of breath, and breathing difficulties. In severe cases, the infection may lead to complications like pneumonia, severe acute respiratory syndrome, kidney failure and sometimes death. The virus has an incubation period of 1-14 days with many symptoms overlapping with the common cold and similar diseases. A recent study revealed the gender bias in COVID-19 as mortality and vulnerability were found to be higher in men compared to women [2]. 2019-nCoV(SARS-CoV2) is an enveloped, positive-sense, single-stranded RNA virus belonging to subgenus Sarbecovirus of the genus Betacoronavirus of Coronaviridae family. This genus also includes Severe Acute Respiratory Syndrome Coronavirus (SARSCoV) and Middle East Respiratory Syndrome coronavirus (MERS). Coronaviruses are spherical with club-shaped glycoprotein spikes or projections on their surface giving it a "corona" or halo-like appearance. Known to have one of the largest viral RNA genomes, the 2019-nCoV has a genome size of 29,891 bp with a GC content of 38% and codes for 9860 amino acids. It codes for 16 non-structural proteins, viz. chymotrypsin-like protease, papain-like protease, helicase, and RNA-dependent RNA polymerase(RdRp), and other non-structural proteins that play role in replication and transcription of the virus. The virus has four structural proteins, viz., spike surface glycoprotein, small envelope protein, matrix protein, nucleocapsid protein, and accessory proteins [3, 4]. Till 17.03.20, complete genomes of a total of 87 strains of the Severe Acute Respiratory Syndrome Coronavirus 2(SARS-CoV2) have been sequenced. Out of these, 48 strains have been isolated from the USA, 28 strains are from China, 2 each from India and Taiwan, and 1 each from Japan, Italy, Brazil, Australia, Sweden, Nepal, and South Korea. Entrez entry on 17.3.2020 suggests the availability of 93 nucleotide sequences, 496 protein sequences, 22 genes and also a complete genome sequence (NC_045512) from the sample of the epicenter Wuhan.