Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) possesses a positive-sense single-stranded RNA genome. Mutations of this genome may occur over time, and while these changes are not unexpected, specific mutations may alter important characteristics of the virus. When viral genomic changes are associated with potential altered transmission, virulence, or vaccine efficacy, they may be identified as a particular SARS-CoV-2 Variant of Concern (VOC). Currently, there are three commonly discussed VOCs.