Omicron variant: Stealth version of new strain detected, could make virus harder to track

A stealthier version of Omicron could make the strain harder to track, with standard Covid-19 tests unable to identify it from other variants.

Scientists have discovered a new “stealth” version of the Omicron Covid-19 variant that could be harder to track, with the Queensland Government confirming they’ve detected a case of the “stealth” strain.

Genetically distinct but falling under the Omicron umbrella, standard PCR tests seem unable to distinguish the new version of the virus from other strains such as Delta or the original Covid-19 strain. Instead the variant needs to be confirmed via testing through whole genome analysis.

Because of this, some researchers are calling the new variant “stealth Omicron”.

As laboratories grapple to understand how the new version – known as BA. 2 – emerged, cases of the strain have already been discovered in South Africa, Canada and Australia reports The Guardian.

The new version of Omicron can’t be distinguished from other variants through PCR tests. Picture: AFP

In response to the discovery, researchers from the University College London Genetics Institute have split the B. 1.1.529 lineage into BA. 1 (the standard Omicron strain) and BA. 2 (the newer strain). Should the BA. 2 strain prove even more transmissible or infectious, it could lead to the World Health Organisation (WHO) classifying it as an additional “variant of concern”.

Announcing Wednesday’s case figures, Queensland’s Health Minister Yvette D’Ath said both lineages of Omicron were now present in the state. It’s believed a man who flew from South Africa to Brisbane tested positive to the BA. 2 strain on Sunday.

Speaking to The Guardian, one researcher said it was “worrying” to see a new variant mutate so quickly with fears the virus detection “is missing a big piece of the puzzle”.

Director of the University College London Genetics Institute, Professor Francois Balloux also said that despite similarities, Omicron, BA. 1 and BA. 2 are “quite differentiated genetically” and “may behave differently”.

The fact that normal PCR tests are unable to detect the new Omicron variant is concerning scientists. Picture: NCA Newswire/Gaye Gerard.

Pfizer offers partial protection against Omicron

Scientists from Durban, South Africa found that the Omicron variant can partially evade the protection from two doses of the Pfizer vaccine.

But in the study, while those fully vaccinated people were mostly able to neutralise the variant, scientists said the booster doses would likely help to fend off infection with the virus even more.

One of the lead scientists, Dr Alex Sigal said the results of the tests were ‘better than he expected’.

“Based on the genome, I thought it would be worse,” he wrote in a tweet. “It looks like it’s mostly a question of quantity – the more antibody, the better.”

“The fact that it still needs the ACE2 receptor (the protein which allows Covid-19 to infect human cells) and that escape is incomplete means it’s a tractable problem with the tools we’ve got.”

As of Tuesday, NSW has also reported 31 cases of the Omicron variant, with Queensland also detecting its first two cases of the strain today.

Originally published as Omicron variant: Stealth version of new strain detected, could make virus harder to track