The new variant is highly transmissible, but experts caution little is yet known about XE, Justin Giovannetti writes in The Bulletin.
XE is potentially 10% more transmissible than omicron.
Global health authorities are keeping a close eye on the new variant and the World Health Organisation has warned it could be up to 10% more transmissible than Omicron’s BA.2 subvariant. For context, BA.2 was potentially the most infectious Covid variant seen before XE and is fuelling new waves of cases around the world. BA.2 is currently the dominant strain in New Zealand. As Stuff explains, in this third year of the pandemic numerous variants, subvariants and recombinations have been detected, but most never spread far. Much isn’t yet known about XE, but early indications have led the WHO to urge caution.
What’s the deal with XE?
The variant was first detected in the UK in mid-January and over 600 cases have now been identified across that country. Unlike omicron and delta before it, XE is a recombinant. That means someone got infected with the two omicron subvariants, BA.1 and BA.2, simultaneously. As the virus replicated in their body, it made mistakes, copying bits of both subvariants and making a new hybrid. Voila, XE. The spike protein in XE was taken from BA.2. That’s the first part of the virus our immune system sees, so someone who was previously infected with BA.2 should have some level of protection. The NZ Herald reports that a 10% boost in transmission advantage is slight, so it’s not an unprecedented threat.
Should you be worried about XE?
Probably not right now. Millions are currently infected with Covid around the world and while the pandemic doesn’t cause as much fear and dread as it once did, we should remain alert. With so many cases, Covid is constantly changing. XE will make its way to New Zealand eventually, especially as border settings are relaxed. The variant is so new, it doesn’t have an official name yet. Jemma Geoghegan, a virologist at the University of Otago, explains:
“XE has not been assigned its own Greek letter yet. For the moment, it belongs to Omicron until significant differences in transmission and disease characteristics, including severity, are identified. So far there is not enough evidence to draw conclusions about the transmissibility, severity or immune evasion properties of XE. It is quite likely this recombinant would possess similar disease characteristics to its ‘parents’, BA.1 and BA.2.”
New Zealand has plans for wider surveillance to pick up new variants.
The country is on watch for XE and other new variants that will arrive. Director-general of health Ashley Bloomfield explained to RNZ that wide national testing is needed as we enter winter. With concerns about the return of flu, after a two year absence, keeping tabs on new variants will inform the country’s health response to Covid and other illnesses. The NZ Herald reports that Bloomfield warned a highly transmissible variant, worse than omicron, could force the return to stricter Covid rules. It won’t be clear for days or weeks whether XE could be that variant.