As ‘stealth omicron’ advances, scientists are learning more

By LAURA UNGAR
AP Science Writer

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. New research is slowly revealing clues about the strain, a descendant of omicron called BA.2. Early research suggests it spreads faster than the original omicron and in rare cases can sicken people even if they’ve already had an omicron infection. There’s mixed research on whether it causes more severe disease, but vaccines appear just as effective against it.