Scientists monitoring new ‘stealth’ version of Omicron

While the omicron variant of the coronavirus is still sweeping the globe, scientists are also watching a new mutation of the variant, which has been called BA.2.

But the World Health Organization has said that BA.2 is not a “variant of concern,” noting there is no evidence so far to suggest that the new subvariant will make transmission, illness severity, or efficacy of vaccines any worse. 

“It is the nature of viruses to evolve and mutate, so it’s to be expected that we will continue to see new variants emerge as the pandemic goes on,” said Dr. Meera Chand in prepared comments.

Chand currently serves as the COVID-19 incident director at the UK Health Security Agency. “So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than omicron BA.1, but data is limited.” 

Around the globe, BA.2 numbers are increasing, with at least 40 countries reporting cases to a tracking database that keeps up with global variants.

The new subvariant, though, has been spreading rapidly in Denmark and the UK, and almost half the number of recent cases in Denmark have been attributed to BA.2. The subvariant was also detected in multiple U.S. states, as Washington State confirmed two cases on Monday. 

Scientists have been able to identify the subvariant using traditional genetic sequencing technology, but it has not been as easy as the BA.1 variant, which has a genetic signature that allows scientists to quickly determine whether the sample is omicron.

Because the BA.2 variant does not have the signature, it has sometimes been referred to as the “stealth” variant, but conventional detection methods for the coronavirus will still work to detect the presence of the virus.

“While it’s important to understand that in the family of omicron, there is a sub-lineage that is potentially more transmissible, it’s not necessarily a cause for panic,” said Dr. John Brownstein, chief innovation officer at Harvard University’s Boston Children’s Hospital. Brownstein also serves as an ABC Medical Correspondent.