Fig. 1.

a SARS-CoV-2 structure and RNA genome encoding for different structural and nonstructural protein constituents. b Spike mutational profile for variants of concern (VOCs). Note that all VOCs contain D614G substitution and, N501Y is present in all of them except the Delta variant. Substitutions in the Beta and Gamma variants are highly similar, especially escape mutations of E484K and K417N/T with the evidence of immune evasion. The Delta variant with L452R mutation inside the RBD region shares similar features to the Beta and Gamma variant in the context of increased transmissibility and immune escape. The Omicron variant is the latest VOC as of December 2021 and harbors many mutations at the spike; with 15 mutations in RBD, Omicron is a highly contagious variant with threatening immune evasion capabilities