As ‘stealth omicron’ advances, scientists are learning more

The coronavirus mutant widely known as “stealth omicron” is now causing more than a third of new omicron cases around the world, but scientists still don’t know how it could affect the future of the pandemic.

Researchers are slowly revealing clues about the strain, a descendant of omicron known as BA.2, while warily watching it become ever more prevalent.

“We’re all keeping an eye on BA.2 just because it has done particularly well in some parts of the world,” including parts of Asia, Africa and Europe, said Dr. Wesley Long, a pathologist at Houston Methodist in Texas.

This week, a technical advisory group for the World Health Organization advised public health authorities to monitor it as a distinct omicron strain.

Overall cases are falling in some places where the variant is becoming more prevalent, offering some hope that the latest troubling version of the virus won’t send cases skyrocketing again as experts try to learn more.