Abstract

ABSTRACTThe New Year began with a new threat to the human health, Severe Acute Respiratory Syndrome (SARS)-CoronaVirus (CoV)-2.SARS-CoV-2 is a novel virus (identified as the cause of coronavirus disease 2019 (COVID-19) that began in Wuhan, China inlate 2019) belonging to the Coronavirus family, the 7th recognized as a human pathogen and the 3rd causing a severe clinicalsyndrome after SARS-CoV (identified in 2002 as the cause of an outbreak of severe acute respiratory syndrome (SARS) andMiddle East Respiratory Syndrome (MERS)-CoV1(was identified in 2012 as the cause of Middle East respiratory syndrome(MERS).[ Lai CC et al; 2020]. Intermediate host played an important role in transmission of coronaviruses from them tohumans such as in case of COVID 19 (pangolins or bats yet to be confirmed), SARS-CoV (masked palm civets), MERS (camel)which arises many questions that why there is need of changing the intermediate host for its survival. In this review we will seethe modifications done in respect for its survival which includes S protein , nucleotide, amino acid substitution, genetic similarityKeywords: S protein, Masked palm civets, Pangolins, RBD (receptor binding domain),