new Covid subvariant Omicron XE has been discovered in the UK amid a high number of overall cases.
The new variant was first identified on January 19, according to the World Health Organisation.
However, UK health officials have said at the moment there is not enough evidence to draw definitive conclusions about the Omicron XE.
What is Omicron XE?
Omicron XE is a so-called recombinant variant which occurs when an individual becomes infected with two or more variants at the same time.
This results in a mixing of their genetic material within the patient’s body.
Several recombinant variants have been identified over the course of the pandemic, so this is not unusual.
XE is a recombinant of the Omicron BA.1 and BA.2 strains, with BA.2 driving most of the UK’s cases.
How many cases have there been?
There have been a total of 637 cases of XE have been confirmed in the UK as of March 25, according to the UK Health Security Agency.
The earliest of these has a specimen date of January 19 this year.
This is likely to be only a tiny fraction of overall cases.
Last week, the Office for National Statistics estimated that around 4.9 million people in the UK had Covid in the week ending March 26 – the highest since its survey began in April 2020.
The hybrid strain has also been detected in Thailand and Hong Kong.
How transmissible is Omicron XE?
In a report published March 29, the WHO said of XE: “Early-day estimates indicate a community growth rate advantage of ~10% as compared to BA.2, however this finding requires further confirmation.
“XE belongs to the Omicron variant until significant differences in transmission and disease characteristics, including severity, may be reported.”
UK health officials said modelling of data between January 15 and March 15 showed XE could have a median growth rate of 9.8% over BA.2.
However, Chief Medical Advisor at the UKHSA Professor Susan Hopkins said: “This particular recombinant, XE, has shown a variable growth rate and we cannot yet confirm whether it has a true growth advantage.
“So far there is not enough evidence to draw conclusions about transmissibility, severity or vaccine effectiveness.”
Does XE have any new symptoms?
It is not currently thought that the sub-variant comes with new symptoms, although much is not yet known about XE.
Frequently reported symptoms of the original strain of Omicron are cold-like, particularly for those who have been vaccinated.
The NHS has recently updated its symptoms list of Covid with an additional nine symptoms.
Now the list of potential signs include shortness of breath, feeling tired or exhausted and an aching body among others, alongside a high temperature, a change in taste or smell, or a persistent new cough.