The Delta variant is currently the predominant variant circulating in Arizona, and has been identified in more than 90% of positive COVID-19 samples sequenced. CDC has reported that the Delta variant is more infectious, particularly in unvaccinated individuals, and spreads more rapidly than earlier variants of SARS-CoV-2. The Delta variant contains a number of mutations in the Spike protein. New mutations are continuously occurring; therefore several sub-lineages are evolving from the parent B.1.617.2 strain, including AY.1, AY.2, and AY.3, and other AY lineages*.
Delta sub-lineages AY.1 and AY.2 are characterized by a Spike K417N mutation, and AY.3 by an Orf1ab I3731V mutation.