Nearly 1 In 4 COVID Cases Belong To New Subvariant: UW Medicine

SEATTLE — New data from the University of Washington suggests that the omicron subvariant BA.2 is gaining ground in the Evergreen State— though it does not appear to be driving an increase in the overall number of new COVID-19 cases.

Just last week, the Washington State Department of Health reported that around 7 percent of Washington's COVID-19 cases were caused by the BA.2 subvariant. Now, UW Medicine's Clinical Virology Laboratory says BA.2 accounts for nearly 25 percent of the cases they sequence.

“It's been sort of slowly creeping up over the last six weeks,” said Dr. Alex Greninger, the virology lab’s assistant director.

Though the subvariant has yet to cause any noticeable surges in COVID-19 case counts or hospitalizations, the CDC says initial studies found that COVID-19 vaccines in general do not fend off BA.2 as well as earlier variants. Vaccines do still offer strong protection against severe COVID-19 symptoms, however. Because BA.2 may be more resilient than the dominant omicron strain, researchers say they're hopeful its presence doesn't grow.

“It’s going to be interesting to see what the end of April, beginning of May, what that time period will look like,” said Greninger.

The BA.2 subvariant was first discovered in January. The subvariant is still being researched, but early data suggests that patients who were infected by omicron may be protected against BA.2 infections, which could limit transmission going forward.

"There are a lot of people out there who got sick with omicron. There are a lot of people out there who didn't get omicron," Greninger said. "Getting three vaccines will protect you, but that also declines as you get to more than three months, four months out – you're starting to see sub-50-percent levels of protection in terms of vaccine effectiveness. And so, we're all sort of susceptible. The good news is that you book that prior immunity through vaccination, or prior infection, and you reduce the severity of the illness."

Another reason for cautious optimism: despite the increasing prevalence of BA.2, Washington is still somewhat ahead of the curve. Nationally, BA.2 accounts for about 35 percent of all new infections, according to data from the Centers for Disease Control and Prevention, and while it has driven some upticks in COVID-19 infections — particularly out east — Washington's case counts continue to decline.

Still, if you're worried about another COVID-19 wave or the potential for another lockdown, Greninger says, try to take advantage of the current situation.

" I think – go travel now. There’s a great time here where there's a short window," Greninger said.