With Omicron currently responsible for almost every new case of COVID-19 recorded worldwide, it is ideally suited to serve as the origin of new mutations that branch off from its genetic lineage.
So ideal it’s already happened, weeks or months ago.
Reports are now emerging of infections caused by a hybrid strain tentatively called Omicron XE. It features aspects from both the initial version, dubbed BA.1, and the BA.2 version known popularly as “stealth” Omicron.
“The transmissibility and the severity of this new recombinant variant is still being investigated, so we’re closely monitoring the latest situation,” said Chuang Shuk-kwan, head of the Communicable Disease Branch at Hong Kong’s Center for Health Protection (CHP), on Friday.
Her comments came after the city’s media reported at least two cases of Omicron XE had already been detected in the Asian financial hub.
Circulating in January or February
The CHP said the cases involved travelers who arrived in the city in February, and claimed there was no evidence to suggest it had spread within the community, given Hong Kong’s strict quarantine policies for travelers. This might explain why CHP has only now confirmed the new XE variant, as it may have believed it stopped the threat of contagion before it escaped.
The new strain appears to have been first detected on Jan. 19 by U.K. authorities. The country’s Health Security Agency has since recorded 637 cases geographically distributed across England by March 22, suggesting community transmission. Statistical models it has run conclude Omicron XE is 9.8% more effective at infecting others than stealth Omicron alone.
“However, this finding requires further confirmation,” the World Health Organization was quoted as writing in a report on Thursday.
Although existing forms of Omicron tend to only lead to mild infections, its infectiousness and ability to evade vaccines have been the two defining traits that allowed it to outcompete Delta.
As a result, China is now facing its worst outbreak since early 2020, with hotspots that include large parts of Shanghai under total lockdown as part of the country’s zero-COVID policy.
Companies like BioNTech, which engineered the world’s first widely approved COVID vaccine in partnership with Pfizer, and Moderna are now using their mRNA technology to develop a vaccine specially adapted to Omicron that can minimize the risk for high-risk groups.
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