DALLAS — UT Southwestern Medical Center in Dallas on Thursday informed Spectrum News 1 that researchers there via its genomic sequencing laboratory detected two cases of variant BA.2, better known as “stealth” omicron.

What You Need To Know

  • UT Southwestern Medical Center in Dallas confirms two cases of the BA.2, or “stealth,” omicron variant have been detected in North Texas

  • This follows the detection of three cases in the Houston area

  • BA.2 is generally considered harder to detect than the original version of the COVID-19 omicron variant

  • Despite confirmation of some cases, BA.2 has yet to gain a foothold in the U.S.

This comes following reports of three cases in the Houston area.

What is it? According to the Associated Press BA.2 is widely considered stealthier than the original version of omicron because particular genetic traits make it somewhat harder to detect. Some scientists worry it could also be more contagious.

But they say there’s a lot they still don’t know about it, including whether it evades vaccines better or causes more severe disease.

Since mid-November, more than three dozen countries have uploaded nearly 15,000 genetic sequences of BA.2 to GISAID, a global platform for sharing coronavirus data. As of Tuesday morning, 96 of those sequenced cases came from the U.S.

“Thus far, we haven’t seen it start to gain ground” in the U.S., said Dr. Wesley Long, a pathologist at Houston Methodist in Texas, which has identified three cases of BA.2.

BA.2 has lots of mutations. About 20 of them in the spike protein that studs the outside of the virus are shared with the original omicron. But it also has additional genetic changes not seen in the initial version.

It’s unclear how significant those mutations are, especially in a population that has encountered the original omicron, said Dr. Jeremy Luban, a virologist at the University of Massachusetts Medical School.

The Associated Press contributed to this report.