Now and for the last couple of weeks, the prevalent coronavirus variant is not Delta, but its subvariants AY.3 and AY.4. They are distinguished from Delta (B.1.617.2) by a set of point mutations in ORF1a.
These mutations in ORF1a might be responsible for the increased rate of growth.
AY.3-AY.4 subvariants represented 25%-30% of sequenced samples since early July, and might be responsible for higher severity of the cases. Now they represent more than 60%.
Work in Progress
via Science Defies Politics
September 2, 2021