The new BA.2 omicron subvariant, regularly referred to as "stealth omicron," has been reported in Wisconsin, according to a Milwaukee County health official.
Dr. Ben Weston, chief health policy adviser for Milwaukee County tweeted Monday that BA.2 had been detected in the state, noting it is 1.5 times more transmissible than the original omicron strain but doesn't appear to be more severe.
It's unclear where exactly in the state the case was reported.
This version of the coronavirus has been detected in more than 40 countries and is widely considered stealthier than the original version of omicron, BA.1, hence its name. Particular genetic traits make BA.2 somewhat harder to detect, health officials have said.
The World Health Organization classifies omicron overall as a variant of concern, but it doesn’t single out BA.2 with a designation of its own. Given its rise in some countries, however, the agency says investigations of BA.2 “should be prioritized."
An initial analysis by scientists in Denmark shows no differences in hospitalizations for BA.2 compared with the original omicron. Scientists there are still looking into this version's infectiousness and how well current vaccines work against it. It's also unclear how well treatments will work against it.
Doctors also don’t yet know for sure if someone who’s already had COVID-19 caused by omicron can be sickened again by BA.2. But they’re hopeful, especially that a prior omicron infection might lessen the severity of disease if someone later contracts BA.2.