A UK Health Security Agency (UKHSA) study recently revealed that currently as many are 3 hybrid COVID variants are circulating.
The two different combinations of Delta and BA.1 are XD and XF. The third is XE. XD is the new name for the French Delta x BA.1 lineage.
It contains the Spike protein of BA.1 and the rest of the genome from Delta. It currently comprises several 10s of sequences.
XF is a UK Delta x BA.1 lineage. It has the Spike and structural proteins from BA.1 but the 5' part of its genome from Delta.