PORTLAND, Ore. — A new COVID wave is underway in Oregon, with new cases and hospitalizations both surging from their post-omicron low points in the past six weeks, largely fueled by the BA.2 version of the omicron variant.
The seven-day average for new cases was 1,300 as of Monday, up from a low point of 229 in late March. Hospitalizations reached a low point of 84 on April 7, but have more than doubled to 199 in the past few weeks.
"I would say that we're in a BA.2 wave that is probably augmented by the fact that we took our masks off at about the same time that the wave started," said Dr. Paul Cieslak, medical director for communicable diseases and immunizations at the Oregon Health Authority.
The OHA is urging Oregonians to keep up with their vaccinations and be mindful of the risk of transmission in public spaces, especially for people with compromised immune systems or who are at high risk of severe disease.
"The virus is being transmitted pretty freely. We estimate that 1% of the population is walking around with it. And so if you're in a crowded room, the chances are good that you're going to be exposed to it," Cieslak said. "So what you need to do is to get your immunity as good as you can get it. In other words, make sure that you're vaccinated and boosted, and then if you're in one of those groups for whom a second booster is available, consider taking advantage of that."
The previous wave was caused by the first omicron version, BA.1, but BA.2 now accounts for a majority of the state's cases. Another version, BA.2.12.1, has been seen to a lesser degree in Oregon, Cieslak said, but others like BA.4 and BA.5 don't seem to have established much of a presence in the state so far.
As the first omicron wave receded, state health officials highlighted 400 COVID hospitalizations statewide as the target for when it would be safe to end the mask mandate, but that doesn't necessarily make 400 the trigger point to reimpose the mandate as hospitalizations rise again.
"I don't think we have a magic number in mind," Cieslak said. "And we continue to be optimistic because with each passing week we have more people vaccinated and we have more people who have survived the COVID-19 infection and gathering immunity that way. So we're pretty optimistic that we won't need to go there."
In any case, the forecast from Oregon Health and Science University predicts the wave will crest before it hits 400 hospitalizations. The latest report projects a peak of 321 hospitalizations on June 10. That accounts for the higher transmissibility of BA.2, Cieslak said, although not the potential arrival of any other new variants.
"So that's always the joker in the pack," he said. "We don't know exactly what we're going to get in that regard."