XD, XE and XF are 3 New Covid Variants that Combine Omicron + Delta and BA.1 + BA 2
The following quotes are from MSN, originally published by HullLive (UK), titled “Scientists keeping watch on mutant covid strain which has seen hundreds of cases,” which can be found here and is quoted below:
UKHSA’s new analysis has looked at the recombinants known as XF, XE, and XD. Of these, XD and XF are recombinants of Delta and Omicron BA.1, while XE is a recombinant of Omicron BA.1 and BA.2.
In the UK, 38 cases of XF have been identified, though none have been seen since mid February.
XD has not been identified in the UK to date. A total of 49 cases have been reported to global databases, the majority of these are in France.
There have been 637 cases of XE – a recombinant of Omicron BA.1 and BA.2 – confirmed in the UK so far.
Also, from Mint (India), from their article published today titled “After Omicron+Delta recombinant, 2 more hybrid Covid strains found; Expert explains how fatal they can be,” which can be found here and is quoted below:
Of the three, two are combinations of Omicron and Delta (different versions), while the third emerged from the mixing of 2 different Omicron subvariants (BA.1 and BA.2).
After Omicron, Delta recombinants were detected in France in mid-February, two more Omicron-related recombinant strains have been tracked. Of the three known strains, two are combinations of Omicron and Delta (different versions), while the third emerged from the mixing of 2 different Omicron subvariants (BA.1 and BA.2). A new study pointed out that research is underway to understand what might be the impact of these new COVID hybrid variants.
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. It comprises several tens of sequences currently.
XE is a large UK BA.1 x BA.2 lineage. It has the Spike and structural proteins from BA.2 but the 5′ part of its genome from BA.1. It comprises several hundred sequences at present.
How worried you should be about the variants?
Eminent virologist Tom Peacock [at the Imperial Department of Infectious Disease in London, England] explained that recombinants that contain the spike and structural proteins from a single virus (like XE or XF) are fairly likely to act similarly to thier parental virus.
XD is maybe a little more concerning. It has been found in Germany, Netherlands and Denmark and it contains the structural proteins from Delta – if any of these recombinants were to act much differently than its parent it might be XD.