Emergence, evolution, and vaccine production approaches of SARS-CoV-2 virus: Benefits of getting vaccinated and common questions

the emergence of coronavirus disease 2019 (COVID-19) pandemic in Wuhan city, China at the end of
2019 made it urgent to identify the origin of the causal pathogen and its molecular evolution, to appro
priately design an effective vaccine. This study analyzes the evolutionary background of the severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2 or SARS-2) in accordance with its close relative SARS
CoV (SARS-1), which was emerged in 2002. A comparative genomic and proteomic study was conducted
on SARS-2, SARS-1, and Middle East respiratory syndrome coronavirus (MERS), which was emerged in
2012. In silico analysis inferred the genetic variability among the tested viruses. The SARS-1 genome har
bored 11 genes encoding 12 proteins, while SARS-2 genome contained only 10 genes encoding for 10 pro
teins. MERS genome contained 11 genes encoding 11 proteins. The analysis also revealed a slight
variation in the whole genome size of SARS-2 comparing to its siblings resulting from sequential inser
tions and deletions (indels) throughout the viral genome particularly ORF1AB, spike, ORF10 and ORF8.
The effective indels were observed in the gene encoding the spike protein that is responsible for viral
attachment to the angiotensin-converting enzyme 2 (ACE2) cell receptor and initiating infection