Even as the omicron COVID-19 variant continues to sweep the globe, scientists are now monitoring a new mutation of omicron, dubbed BA.2.
The World Health Organization maintains that BA.2 is not a “variant of concern,” meaning there is no current evidence to suggest this new subvariant will worsen COVID-19 transmission, illness severity, or efficacy of vaccines and public health efforts like masking and social distancing.
The subvariant has already been detected in several U.S. states, with Washington State confirming two cases Monday.
While over 8,000 BA.2 cases have been identified since November 2021, it is unclear where BA.2 originated. Even though the first sequences were submitted from the Philippines, numerous cases have since been detected in various places, from Europe to South Asia.
Given the rising numbers, health care organizations, like the WHO, are asking scientists to watch and study the new subvariant separately from omicron, to see if it behaves differently.
Conventional COVID-19 tests can show a positive or a negative result, but they can’t determine specific variants. For that, scientists need to do additional genetic sequencing. Conveniently, the omicron variant has a particular genetic signature that allows scientists to quickly and easily determine if the sample is omicron or not.
The new BA.2 subvariant does not have that feature, meaning scientists can no longer use this shortcut — though they can still identify the subvariant using genetic sequencing technology. Because of this, the BA.2 subvariant has sometimes been referred to as the “stealth” variant. But for the general public, conventional COVID-19 tests will still work to detect the new subvariant.
Ultimately, while scientists and public health officials are urging continued research and surveillance, experts say there is little reason to worry.
“BA.2 is important from a public health perspective, but it doesn’t fundamentally change at this moment, how we think about the impact in the population,” Brownstein said. “A lot more work needs to be done to understand severity, breakthrough infections, and immunizations before you can make any statement about clinical relevance.”
“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,” Brownstein added.