Scientists say they have discovered a “sister” of the mutated COVID-19 variant Omicron.
In an announcement on the discovery, health officials warn that the new lineage is “much harder to track.”
A South African man in Queensland who tested positive for Omicron has a genetically different version of the virus that experts have dubbed “Omicron Like.”
The “sister” was identified when the man, who returned to Australia from the Omicron epicenter South African province of Gauteng last week, came down with Covid while isolating at a Brisbane hotel quarantine facility.
Queensland’s health minister Yvette D’Ath confirmed the case meant Omicron has now been classified into two lineages by the international committee.
“We are standing here announcing a new version of Omicron and it’s a first in the world,” she said in a statement.
Cases of Omicron-like are also being reported in South Africa and Canada though none have yet been reported in the UK.
While information is still emerging, one key difference of Omicron Like is that the new sister lineage is missing a genetic quirk used by health officials to track the spread of the original super-mutant strain.
Known as the S gene dropout, this aspect of Omicron meant it can be detected using a relatively simple PCR test, as opposed to more complicated lab tests.
The fact that Omicron Like does not have this S gene dropout means this shortcut cannot be used, meaning it will be harder to track as an outbreak.
There is no information currently on if Omicron Like is anymore, or even less, infectious or if it has the potential to impact on vaccine effectiveness, though it has fewer mutations than original Omicron.
Queensland’s Chief Health Officer Peter Aitken said experts were able to distinguish between the two types of Omicron genetically.
“[They] recognized there are differences between the full and normal Omicron classification, passed it on to the international committee in a really quick time frame,” he said.
“This now led to a re-classification of Omicron.
“It (Omicron Like) has enough genes to be classified as Omicron, but we don’t know enough about it for what that means as far as clinical severity, vaccine effectiveness.
“What we do know is that Omicron is more infectious and more transmissible.”