A review of the emergence of the new variants of the SARS-CoV-2 in the world

Abstract

A new infectious disease responsible for the emergence of respiratory syndrome and caused by the virus called coronavirus (SARS-CoV-2) was detected in late 2019 in Wuhan. Coronaviruses are a group of viruses, belonging to the family Coronoviridae of the order Nidoviridales and are responsible for causing, mainly, respiratory and gastrointestinal tract infections. SARS-CoV-2, despite predominantly infecting birds, has been responsible for the third major coronavirus outbreak in the last 20 years. In March 2020 the World Health Organization (WHO) declared the outbreak of COVID-19 cases to be a pandemic, and in October of the same year more than 1.04 million deaths were recorded.