The CDC announced this week that the BA 2 Omicron variant, which is said to be 30% more transmissible than the original Omicron strain BA.1 — has become dominant among the new cases classified by the United States. That’s an astonishing rise for a variable that was less than 1% of all series through January. But just as Americans hear about BA.2, there is actually a newer, more portable variant that is on the rise.
There are actually three new variants set. As per their recent release, the two are called XD and the XF is a mix of Delta and BA.1, or so called “deltacrone” strains that have been talked about for months but haven’t made much progress in any country.
XD is present in several European countries but has not been detected in the UK, according to the report. XF has set up a small conglomerate in the UK but has not been found there since February 15th.
Like other newcomers, XE is a recombinant breed, which means that it was previously made up of two different species. But it is not a mixture of Deltacron. XE already consists of the original Omicron (BA.1) and the newer Omicron (BA.2) acquired by the United States.
Omicron BA.2 variant now dominant in the US; Hit the Northeast hard
The World Health Organization released a report yesterday that includes some preliminary findings about XE.
“Recombinant XE was first detected in the UK on January 19 and more than 600 sequences have been reported and confirmed since then,” she says. Who is the document? “Early days estimates suggest a community growth rate advantage of about 10% over BA.2, but this finding requires further confirmation.”
The additional focus is increasing day by day, according to the World Health Organization, which this week registered concerns about what it calls “the recent significant decline in SARS-CoV-2 testing by many member states. The data is gradually becoming less representative, less current and less robust. This hinders Our collective ability to track where the virus is, how it is spreading and how it is evolving – the information and analysis that remains critical to effectively ending the acute phase of a pandemic.
The Covid BA.2 Omicron variant is now likely responsible for the majority of new cases in Los Angeles
In recent weeks, instructions from the UK’s Health Services Agency have reinforced some of the WHO’s report’s claims and urged caution in drawing conclusions. One difference between the two documents is that WHO data and analysis appears to be more recent.
From the UK HSA Briefing:
XE shows evidence of community transmission within England, although it is currently less than 1% of all serial cases. XE’s early growth rates were not significantly different from BA.2, but based on the most recent data as of March 16, 2022, XE has a 9.8% higher growth rate than BA.2. Since this estimate did not remain constant when new data were added, it cannot be interpreted as an estimate of the growth advantage over the recombinant. The numbers were too small for the XE recombinant analysis by region.
To be clear, XE represents only a small fraction of cases worldwide. That may change, as XE is thought to be about 10% more convertible than BA is already more convertible. This means it could be about 43% more portable than the original Omicron Wild Earth last winter.
But a new wave of infections from the now-dominant BA.2 hasn’t materialized, even with the loosening of restrictions. So we hope that the trend with XE, in the case of competition with BA.2, will be similar. Only time – and good observation – will tell.
