COVID-19 has constantly evolved since it first began to spread across the World in late 2019. Genomic sequencing efforts, as visualized in the map and chart, provided insight that the virus was not mutating rapidly with a common change. It wasn’t until late 2020, that variants of concern, Alpha, Beta, Gamma, and Delta started to appear with spike protein mutations. Changes in the spike protein can influence the virus binding ability to a healthy human cell in order to enter and infect it, or even how well antibodies from vaccines can bind to block viral entry.
The increase of fitness these viruses caused them to spread rapidly over 2021. As illustrated in the animations, the viruses have competed at times to be the dominant virus. The Beta and Gamma variants spread across their localized region of origin, South Africa and Brazil, but both Alpha and Delta have had global spread. At time points, the dominant virus switched and currently we are faced with the Delta variant.
The original virus and similar variants have been replaced with no reason to expect this evolutionary path of variants will stop anytime soon. Current vaccines are almost exclusively focused on the mutating spike protein, and a number of breakthrough infections have occurred. Fortunately, antibody vaccine responses have largely maintained protection. As the virus continues to compete and evolve, new approaches targeting proteins of the virus that do not mutate into driving variants could provide a path forward toward ending the COVID-19 pandemic.