What we know about the XBB.1.5 COVID subvariant in the Twin Cities

A new Omicron subvariant is spreading rapidly throughout the nation, but has yet to set off a new wave of COVID cases in the Twin Cities — and experts aren't sure if it ever will.

The big picture: The variant, known as XBB.1.5, is believed to be the most transmissible form of Omicron to date. Health experts say it's to blame for a recent surge in cases in the Northeast U.S.

Yes, but: In Minnesota, cases and hospitalizations remain flat, even after holiday travel and gatherings.

• The latest Twin Cities wastewater surveillance data, released Friday, actually showed total virus levels decreasing by 12% week over week.

What they're saying: Michael Osterholm, director of the University of Minnesota's Center for Infectious Disease Research and Policy, told Axios "no one knows" whether the variant will take off locally.

• "We could see only a very limited increase in cases associated with it, or we could, in four to six weeks, see exactly what's happening in the Northeast," he said. "We just don't know."

Between the lines: While high immunity levels due to previous infections and vaccinations likely help, experts don't fully understand how these new variants behave.

• The Alpha strain, which was dominant in late 2020 and early 2021, hit Minnesota and Michigan particularly hard, but didn't spread to other parts of the country, Osterholm noted.

Another unknown: State epidemiologist Ruth Lynfield said it's "hard to know" if new variants will have a big impact on hospitalizations or deaths.

• Worries about the "tripledemic" crisis are fading, as flu and RSV cases decline. But even a small COVID spike could strain hospitals, which are already experiencing staffing issues, she said.

What to watch: While the subvariants aren't driving up cases yet, recent wastewater data shows that XBB is making up 27% of the total viral load in the Twin Cities, up from 15% the week before.

Be smart: Lynfield cautioned that Minnesotans should be mindful that the new variant is more infectious and immune resistant.

• She encourages Minnesotans to get a booster shot and wear N95/KN95 masks in crowded settings.
• Those who do test positive at home can get a prescription for antivirals via a telehealth app launched by the state last month.