Omicron subvariant goes from 7% to 25% of local cases within a week

BA.2, the omicron subvariant of COVID-19 that’s causing a surge in parts of Europe and Asia right now, is also increasing in Washington state.

As recently as last week, the Washington State Department of Health said the presence of the subvariant — which was first detected in Washington in late January — was minimal.

“Our percent of that subvariant remained less than 7%, so we are remaining very low in our subvariant,” said Dr. Scott Lindquist, the state’s epidemiologist, during last week’s briefing. “It is not becoming the dominant force, and it is certainly not driving an increase in cases.”

UW virologist: ‘Every chance’ omicron subvariant precipitates ‘endemic state’ of COVID

But BA.2’s presence has grown substantially in the seven days since then. In clips provided to KIRO Newsradio by UW Medicine, UW Clinical Virology Lab Assistant Director Dr. Alex Greninger said the BA.2 subvariant makes up about a quarter of all new cases they are sampling.

“We are actually running along with what the CDC is showing, so we are around 25% of cases detected are BA.2,” Greninger said. “It’s been sort of slowly creeping up over the last six weeks.”

While previous variant-fueled waves, like delta last summer and omicron over the winter, began in Europe and Asia before having the same rapid rise in the United States, Greninger said there is no guarantee that we will follow our counterparts around the world this time.

“I don’t have any predictions,” Greninger said.

Working in our favor is the large number of omicron infections during the December and January surge.

“There’s great data that shows that BA.1 infection [the earlier form of omicron] does protect against BA.2,” Greninger said. “They’re very similar in that world from an immunological standpoint.”

The state’s high vaccination rate — 81% of the population age 5 and up has received one dose — also helps overall immunity.

Still, Greninger said we are likely to see an uptick in cases in April — the question is, how big. Greninger does not see it being as bad as the previous omicron wave, but this subvariant does appear to be more contagious than the “original” omicron.

“There’s a lot of people out there who got sick with omicron. There’s also 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 sort of more than three months, four months out.”

The good news is that COVID cases in Washington are still dropping rapidly, with daily case rates at levels lower than we have seen in nearly a year.

Greninger says the next few weeks will tell us what we can expect, but the best things to do are to get all of your shots, wear a mask in crowds, and stay home if you feel ill.

“It’s going to be interesting to see what end of April, beginning of May looks like,” Greninger said.

As for that spring trip? You might want to hop on those travel websites tonight.

“Go travel now — this is a great time here while there’s a little short window,” Greninger said.

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