‘Stealth' Omicron Detected as New Case Numbers Confirmed

UT Southwestern says it has confirmed two cases of the "stealth" omicron strain, BA.2 in North Texas.

Doctors didn't provide case details of patients.

The new subvariant of omicron has been dubbed "stealth" because it is more difficult to detect on some PCR tests.

"There are two things that I think grabbed scientists' attention," said UT Southwestern Associate Professor Dr. James Cutrell.

"The first one was that this BA.2 variant had some collection of different mutations in the spike protein that made it a little bit harder to pick up on some of the standard commercial PCR tests that were being done on omicron."

"The second thing that I think got people's attention was, particularly in Denmark and in some of the countries in Europe, it seemed like that as a proportion of the total cases, this BA.2 was increasing in its percentage. So that's led some people to speculate that it could be that this variant could have some slight transmission, or might be slightly more contagious than the original omicron variant," said Dr. Cutrell.

According to information from the Danish government, BA.2 isn't more deadly than omicron. They say initial analysis shows no differences in hospitalizations for BA.2 compared to BA.1. It is expected that vaccines also have an effect against severe illness upon BA.2 infection.

BA.2 is increasing in many countries, suggesting there might be a transmissibility advantage over the original omicron strain.

Still, the prevalence of this variant here in the U.S. is very low, with fewer than 0.5% of all cases.

The new subvariant is not considered a “variant of concern" by the World Health Organization.

The sub-variant's presence won't change the trajectory of the pandemic, said Cutrell.

According to the latest UTSW COVID-19 projections, the number of people hospitalized in both Dallas and Tarrant County appears to have plateaued at current high levels.

The test positivity rates appear to be declining, and both emergency room visits and new hospital admissions are declining or flat in most age groups.

The report says the worst-case scenarios of recent forecasts have been avoided thanks to recent increases in masking and increases in time spent at home, likely
implying that many people are responsibly quarantining when exposed and/or isolating when sick.

The "stealth" subvariant of omicron won't change anything in terms of the on-the-ground response and what people need to be doing, said Cutrell.

"Doctors and the hospitals are still going to be treating and taking care of patients the same way. The same tests that we have to detect this virus are still going to work. The same treatments and the same preventive measures like vaccination, masking and all of these other things that we've learned work, those are all still going to be the same things that we need to do," said Cutrell.