North Texas public health experts remain cautiously optimistic that the highly-contagious COVID-19 strain BA.2 won’t set off waves of new cases or hospitalizations, even as case numbers climb in parts of the Northeast.
BA.2 is a more-contagious subvariant of the original omicron lineage, called BA.1. The variant, which the World Health Organization declared the dominant strain circulating worldwide, was first detected in North Texas in January through UT Southwestern Medical Center genetic testing.
Case counts in some places, like New York City, are increasing as BA.2 picks up speed, although they remain low compared to January’s omicron surge. North Texas COVID-19 case counts continue to fall, approaching the lowest numbers seen in about a year, said Dr. Jeffrey SoRelle, who is leading UT Southwestern’s COVID-19 variant tracking effort.
BA.2 accounts for about 20% of COVID cases in North Texas, SoRelle said, up from around 12% two weeks prior.
“It’s gradually increasing,” he said. “But, it’s hard to get a firm estimate on that just because we’re getting so many fewer cases. The precision is kind of reduced with that.”
In the latest COVID-19 forecast, released Wednesday with data from March 21, UT Southwestern researchers projected that new COVID infections in Dallas County will remain around 100 per day for the next several weeks. In Tarrant County, projected COVID cases remain below 100 per day.
Hospitalizations in the two counties are following suit.
“The number of people hospitalized in Dallas County is expected to level off at near-record lows this week, and Tarrant County is expected to follow suit next week,” the forecast said. “These low levels are predicted to persist for the next several weeks.”
BA.2 is growing even more slowly in other parts of the state than in the Dallas area. At Houston Methodist, BA.2 accounted for only 1% to 3% of sequenced case batches, said Dr. Wesley Long, medical director of diagnostic microbiology at Houston Methodist.
Public health experts expect most Americans have some protection from severe illness by BA.2 because the subvariant responds to omicron antibodies. Omicron caused a near-record high in coronavirus cases and hospitalizations at the start of the year.
One of the theories as to why BA.2 has been slow to take over the dominant variant in Texas is because of the state’s more lenient protective measures during the omicron surge, said Catherine Troisi, an infectious disease epidemiologist with the University of Texas Health Science Center at Houston.
“We didn’t have the protective measures, the mask mandates and vaccine mandates, that New England and other parts of the Northeast had,” she said. “A lot of people [in Texas] got infected [with omicron], so now we just don’t have as many people who, at least right now, can be infected.”
While Dallas County did have a mask mandate in place during the omicron surge, it was mostly in name only, as there were no penalties for violating the requirement. Since then, Dallas County Judge Clay Jenkins lifted the mask mandate for most areas in the county.
But health experts are wary that the state of COVID-19 in North Texas could change rapidly. Factors like the weather, which influences whether people gather inside or outside, and waning immunity could lead to increased spread of the virus.
“Parkland is absolutely monitoring the BA.2 situation abroad, nationally and locally,” said Dr. Joseph Chang, chief medical officer at Parkland Health. “I always have concern that the COVID situation could change quickly.”
Long said he imagines Texas will, at some point, see a change in what COVID-19 variant is dominant, be it BA.2 or another strain.
“Maybe it’ll be more of a speed bump than a big wave or surge,” he said. “It’s just really hard to know.”