Genetic Mutations and Strain Dynamics of SARS-CoV-19: A Comprehensive Study

Coronaviruses infect humans with varying degrees of severity and lethality. Four of these viruses(NL63, 229E, OC43, and HKU1) cause mild respiratory problems in humans and three others (MERS CoV, SARS CoV including the newly emerged SARS CoV 2) can cause severe respiratory syndromes. SARS CoV 2 infection was first reported from Wuhan, China, on 24th December 2019 and in less than three months, on 11th March 2020, WHO declared COVID 19 as a pandemic. By 3rd May, 2020, 3.3 million people worldwide (213 countries) were reportedly infected and 2,38,628 individuals died of COVID 19. We note that while the infectivity of SARSCoV 2 is much higher than SARS CoV or MERS CoV , its case fatality rate (0.9 3.3%) is substantially lower than that of SARS CoV (11%) and MERS CoV (34%). For SARS CoV 2, there are notable differences in case fatality rate and disease severity among geographical regions and among age groups of infected persons, with lower severity in infants and children than in adults (1:9). The case fatality rates increased in East Asia(China and neighbourhood) and Middle East (Iran and neighbourhood) have been substantially higher than in Europe (Italy, France and Spain). By March 11, 2020 the corona virus has been changing mutations like A, A2, A2a, B, B1, B1a, B4, B2, A1a, A3, A6, A7, A2a1, A2a1a, A2a2 or A2a2a it was assigned to, based on non-missing sites. The World Health Organization (WHO) made the assessment that COVID 19 should be characterized as a pandemic. At great economic cost, many countries have adopted unprecedented measures to curb the spread of the virus such as large scale use of isolation and quarantine, closing their borders, limits of public gathering and nation wide lockdowns.